Travis: Switch from precise to default dist and manually install open…

…jdk6

- this should fix failing builds

.travis.yml

@@ -1,17 +1,15 @@
-sudo: false
-
 language: java
 
-# precise required for openjdk6, see https://github.com/travis-ci/travis-ci/issues/8199
-dist: precise
-
 jdk:
   - openjdk6
 #  - openjdk7
 #  - oraclejdk7
   - oraclejdk8
 
 addons:
+  apt:
+    packages:
+      - openjdk-6-jdk
   sonarcloud:
     organization: "uwolfer-github"
     token: $SONAR_TOKEN
@@ -24,6 +22,16 @@ cache:
     - $HOME/.m2/repository/
     - $HOME/.sonar/cache/
 
+install:
+  - if [[ "$TRAVIS_JDK_VERSION" == "openjdk6" ]]; then
+      echo "Downloading Maven 3.0";
+      wget https://archive.apache.org/dist/maven/binaries/apache-maven-3.0-bin.zip || travis_terminate 1;
+      unzip -qq apache-maven-3.0-bin.zip || travis_terminate 1;
+      export M2_HOME=$PWD/apache-maven-3.0;
+      export PATH=$M2_HOME/bin:$PATH;
+      mvn -version;
+    fi
+
 after_success:
   if [ "$TRAVIS_JDK_VERSION" == "oraclejdk8" ]; then
     mvn clean cobertura:cobertura coveralls:report jacoco:prepare-agent test jacoco:report sonar:sonar;