Erros no Gradle sync

Meu gradle sync está dando erro nas dependencias abaixo:

C:\Trabalho\Workspaces\Android\Agenda\app\build.gradle Error:Error:line (28)Failed to resolve: junit:junit:4.12 Error:Error:Failed to resolve: javax.inject:javax.inject:1 Error:Error:Failed to resolve: javax.annotation:javax.annotation-api:1.2 Error:Error:Failed to resolve: com.google.code.findbugs:jsr305:2.0.1 Error:Error:Failed to resolve: org.hamcrest:hamcrest-library:1.3 Error:Error:Failed to resolve: org.hamcrest:hamcrest-integration:1.3 Error:Error:Failed to resolve: com.squareup:javawriter:2.1.1

Pergunto, como posso corrigir isto?

Abaixo o código da configuração do Projeto:

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        jcenter()
        mavenCentral()

    }
    dependencies {
        classpath 'com.android.tools.build:gradle:2.3.3'

        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        mavenCentral()
    }
}

task clean(type: Delete) {
    delete rootProject.buildDir
}