Abrir o projeto no Ubuntu

Seu projeto está com alguma dependência para o connector jdbc ? Acredito que esteja faltando o mysql connector: https://dev.mysql.com/downloads/connector/j/

Eu até já tentei a instalação do connector, mas persiste no mesmo erro. Só por garantia esse é meu pom.xml (semelhante ao do projeto final)

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.casadocodigo</groupId>
  <artifactId>casadocodigo</artifactId>
  <version>1.0.0-SNAPSHOT</version>
  <packaging>war</packaging>
  <build>
    <finalName>casadocodigo</finalName>

    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-dependency-plugin</artifactId>
            <version>2.3</version>
            <executions>
                <execution>
                    <phase>package</phase>
                    <goals><goal>copy</goal></goals>
                    <configuration>
                        <artifactItems>
                            <artifactItem>
                                <groupId>com.github.jsimone</groupId>
                                <artifactId>webapp-runner</artifactId>
                                <version>9.0.8.0</version>
                                <destFileName>webapp-runner.jar</destFileName>
                            </artifactItem>
                        </artifactItems>
                    </configuration>
                </execution>
            </executions>
        </plugin>
    </plugins>
  </build>

   <properties>
    <failOnMissingWebXml>false</failOnMissingWebXml>
    <maven.compiler.source>1.8</maven.compiler.source>
    <maven.compiler.target>1.8</maven.compiler.target>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>

<!--     <spring.version>4.1.0.RELEASE</spring.version> -->
<!--     <spring.security.version>4.0.0.RELEASE</spring.security.version> -->

    <!-- https://docs.spring.io/spring-security/site/docs/4.2.6.RELEASE/reference/htmlsingle/#maven-bom -->
    <spring.version>4.3.17.RELEASE</spring.version>
    <spring.security.version>4.2.6.RELEASE</spring.security.version>
    <hibernate.version>4.3.11.Final</hibernate.version>
    <mysql.connector.version>5.1.46</mysql.connector.version>
  </properties>

  <dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>${spring.version}</version>
    </dependency>
    <dependency>
        <groupId>org.apache.tomcat</groupId>
        <artifactId>tomcat-servlet-api</artifactId>
        <version>8.0.36</version>
        <scope>provided</scope>
    </dependency>
    <dependency>
        <groupId>javax.servlet.jsp</groupId>
        <artifactId>jsp-api</artifactId>
        <version>2.1</version>
        <scope>provided</scope>
    </dependency>

    <dependency>
        <groupId>javax.servlet.jsp.jstl</groupId>
        <artifactId>jstl-api</artifactId>
        <version>1.2</version>
        <exclusions>
            <exclusion>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

    <dependency>
        <groupId>org.glassfish.web</groupId>
        <artifactId>jstl-impl</artifactId>
        <version>1.2</version>
        <exclusions>
            <exclusion>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
            </exclusion>
        </exclusions>
    </dependency>

Continuação

    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-api</artifactId>
        <version>1.6.1</version>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>jcl-over-slf4j</artifactId>
        <version>1.6.1</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>org.slf4j</groupId>
        <artifactId>slf4j-log4j12</artifactId>
        <version>1.6.1</version>
        <scope>runtime</scope>
    </dependency>
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.16</version>
        <scope>runtime</scope>
    </dependency>

    <!-- dependencias hibernate e jpa -->
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-entitymanager</artifactId>
        <version>${hibernate.version}</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-core</artifactId>
        <version>${hibernate.version}</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate.javax.persistence</groupId>
        <artifactId>hibernate-jpa-2.1-api</artifactId>
        <version>1.0.0.Final</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>${spring.version}</version>
    </dependency>

    <!-- dependencia driver mysql -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-

Faltou um pedaço do pom, ficou mysql-connector-

é verdade, nem vi que ficou faltando essa parte aqui:

    <!-- dependencia driver mysql -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.17</version>
    </dependency>

    <!-- dependencia driver postgres para heroku -->    
    <dependency>
        <groupId>org.postgresql</groupId>
        <artifactId>postgresql</artifactId>
        <version>9.4-1201-jdbc41</version>
    </dependency>

    <!-- dependencias da api de validação -->
    <dependency>
        <groupId>javax.validation</groupId>
        <artifactId>validation-api</artifactId>
        <version>1.0.0.GA</version>
    </dependency>
    <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-validator</artifactId>
        <version>4.3.2.Final</version>
    </dependency>

    <!-- dependencias para trabalhar com json -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.5.1</version>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.5.1</version>
    </dependency>

    <!-- dependencias do guava (cache) -->
    <dependency>
        <groupId>com.google.guava</groupId>
        <artifactId>guava</artifactId>
        <version>25.0-jre</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context-support</artifactId>
        <version>${spring.version}</version>
    </dependency>

    <!-- dependencias do spring security -->
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-config</artifactId>
        <version>${spring.security.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-taglibs</artifactId>
        <version>${spring.security.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-web</artifactId>
        <version>${spring.security.version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-core</artifactId>
        <version>${spring.security.version}</version>
    </dependency>

    <!-- dependencias email -->
    <dependency>
        <groupId>javax.mail</groupId>
        <artifactId>mail</artifactId>
        <version>1.4.7</version>
    </dependency>

    <!-- dependencias de teste -->
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>${spring.version}</version>
        <scope>test</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.security</groupId>
        <artifactId>spring-security-test</artifactId>
        <version>${spring.security.version}</version>
        <scope>test</scope>
    </dependency>

    <!-- dependencia para java 9 ou superior -->
         <dependency>
            <groupId>javax.xml.bind</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.2.7</version>
        </dependency>
        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.20.0-GA</version>
        </dependency>

</dependencies>    


</project>