Erros ao iniciar o servidor - maven

Boa tarde, estou tentando executar o servidor e está dando os seguintes erros: https://gist.github.com/anonymous/6c2c3dd97979b868434d540291a69618

o meu pom.xml está da seguinte forma:

<?xml version="1.0" encoding="UTF-8"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <modelVersion>4.0.0</modelVersion>
  <groupId>org.casadocodigo</groupId>
  <artifactId>casadocodigo</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <repositories>
    <repository>
      <id>JBOSS_NEXUS</id>
      <url>http://repository.jboss.org/nexus/content/groups/public</url>
    </repository>
  </repositories>
  <dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>4.1.0.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.apache.tomcat</groupId>
        <artifactId>tomcat-servlet-api</artifactId>
        <version>7.0.30</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>

    <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>
</dependencies>
  <build>
    <finalName>casadocodigo</finalName>
    <plugins>
      <plugin>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.1</version>
        <configuration>
          <source>1.6</source>
          <target>1.6</target>
          <encoding>UTF-8</encoding>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

O que pode está havendo?