[ci] Use openjdk11 for building, add osx into the build matrix

* Allow travis to cache jdk
* cache $HOME/.rvm, install bundler with current rvm ruby (needed for osx)

.travis.yml

@@ -1,5 +1,3 @@
-dist: trusty
-sudo: false
 addons:
   ssh_known_hosts:
     - web.sourceforge.net
@@ -16,14 +14,33 @@ env:
   - secure: "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"
   - secure: "gqyPF3d75JuwZptnQQQKO6rGUILXGO09y9dZhShdX8qq5Mexa2ISk77Y/b0yyAdhJMgEglls5cWlbHkwCAB0i4yL25RE5CtQUe4er+CIKwBIs0M56ghbcOwWAFB/cXeyyWmXDHBVnVUeKm7IJ34txsEclnMzQSR/DInSzsCFMUQok8HEaWZNssMjyRgo6goKGdG5vNWGfLLY7mKGMe/6PpYJD0G8k+Na08aX06ZWph38He8O3imUAngoQrxiSp0UYmnHDkigbV7S2LdZOsj7kMxkiyigzK/P1eygHVbFAhohLroaqS9B4CBK7QeOyup2vxVKqJVzFwOCylD0786CImvaG2ZYMtvJkapvaEE0mdMlyYpHgdIkmHZu28aMW7hXEhxHyBAxKuPcj5eGCGziO+ztCvfYIA9CGs1uA4KLrED7SahvB0oXnt3KTFdRc857cWcpp2NmRKihLzVdgHlmT8zcYaec3zP1VdMoa2bmLHoaZtAwvMTcAG56FcET1p7f9v+uiU88ZeptEjTJfpAWlq34tpwZXNyIQi5IROocSHM+PKTgLAsAMP5klGascr8E0sEzREl7tg8hqEwXKym/sVKyT+HMptA3UZcrZZhm07/cmQ0pUVvbV9QDb0MzU3O2wF7vT3U7R7Fb1u0LxMjblPyEazTp8ldabVRJREwlsDc="
   - secure: "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"
-  matrix:
-  - BUILD=deploy
-  - BUILD=doc
-  - BUILD=sonar
-  - BUILD=coveralls
 
 matrix:
   fast_finish: true
+  include:
+    - name: "linux - mvn deploy"
+      os: linux
+      dist: trusty
+      sudo: false
+      env: BUILD=deploy
+    - name: "linux - build documentation"
+      os: linux
+      dist: trusty
+      sudo: false
+      env: BUILD=doc
+    - name: "linux - run sonar"
+      os: linux
+      dist: trusty
+      sudo: false
+      env: BUILD=sonar
+    - name: "linux - run coveralls"
+      os: linux
+      dist: trusty
+      sudo: false
+      env: BUILD=coveralls
+    - name: "macosx - mvn verify"
+      os: osx
+      env: BUILD=deploy
 
 before_install:
   - wget https://github.com/sormuras/bach/raw/master/install-jdk.sh
@@ -31,9 +48,10 @@ before_install:
   - bash .travis/configure-maven.sh
   - rvm install 2.4.1
   - rvm use 2.4.1
-# Install OracleJDK 10 - see https://sormuras.github.io/blog/2018-03-20-jdk-matrix.html
+# Install OpenJDK 11 - see https://sormuras.github.io/blog/2018-03-20-jdk-matrix.html
 install:
-  - . ./install-jdk.sh -F 10 -L BCL
+  - . ./install-jdk.sh -F 11 -L GPL -W $HOME/jdk
+  - gem install bundler
   - bundle install
 before_script: true
 script: source .travis/build-$BUILD.sh
@@ -71,7 +89,8 @@ notifications:
 cache:
   directories:
   - "$HOME/.m2"
-
+  - "$HOME/jdk"
+  - "$HOME/.rvm/"
 
 # Secure Keys, that need to be set for snapshot builds
 #

.travis/build-deploy.sh

@@ -48,7 +48,12 @@ log_info "Building PMD ${VERSION} on branch ${TRAVIS_BRANCH}"
 
 MVN_BUILD_FLAGS="-B -V"
 
-if travis_isPullRequest; then
+if travis_isOSX; then
+
+    log_info "The build is running on OSX"
+    ./mvnw verify $MVN_BUILD_FLAGS
+
+elif travis_isPullRequest; then
 
     log_info "This is a pull-request build"
     ./mvnw verify $MVN_BUILD_FLAGS

.travis/common-functions.sh

@@ -10,6 +10,7 @@ echo "TRAVIS_SECURE_ENV_VARS: ${TRAVIS_SECURE_ENV_VARS}"
 echo "TRAVIS_BRANCH: ${TRAVIS_BRANCH}"
 echo "TRAVIS_TAG: ${TRAVIS_TAG}"
 echo "TRAVIS_ALLOW_FAILURE: ${TRAVIS_ALLOW_FAILURE}"
+echo "TRAVIS_OS_NAME: ${TRAVIS_OS_NAME}"
 
 function travis_isPullRequest() {
     if [ "${TRAVIS_REPO_SLUG}" != "pmd/pmd" ] || [ "${TRAVIS_PULL_REQUEST}" != "false" ]; then
@@ -27,6 +28,14 @@ function travis_isPush() {
     fi
 }
 
+function travis_isOSX() {
+    if [[ $TRAVIS_OS_NAME == 'osx' ]]; then
+        return 0
+    else
+        return 1
+    fi
+}
+
 function has_docs_change() {
     if [[ $(git diff --name-only ${TRAVIS_COMMIT_RANGE}) = *"docs/"* ]]; then
         log_info "Checking for changes in docs/ (TRAVIS_COMMIT_RANGE=${TRAVIS_COMMIT_RANGE}): changes found"