Travis-CI 支持 JDK6 和 Maven 3.2.5

Travis-CI 目前默认不支持JDK 6 和 Maven 3.2.5了。

#.travis.yml
language: java

addons:
  apt:
    packages:
      - openjdk-6-jdk

jdk:
  - oraclejdk8
  - openjdk7
  - openjdk6

before_install:
  - echo "Downloading Maven 3.2.5" 
   && wget https://archive.apache.org/dist/maven/maven-3/3.2.5/binaries/apache-maven-3.2.5-bin.zip 
   && unzip -qq apache-maven-3.2.5-bin.zip 
   && export M2_HOME=$PWD/apache-maven-3.2.5 
   && export PATH=$M2_HOME/bin:$PATH 
   && mvn -version