rework travis-ci builds

.travis.yml

@@ -1,24 +1,27 @@
 env:
    - TERM=dumb
 language: java
-jdk:
-  - openjdk7
-  - oraclejdk7
-  - oraclejdk8
 matrix:
+  include:
+    - os: linux
+      jdk: openjdk7
+    - os: linux
+      dist: precise
+      jdk: oraclejdk7
+    - os: linux
+      jdk: oraclejdk8
+    - os: linux
+      dist: trusty
+      jdk: openjdk8
+    - os: osx
   allow_failures:
     - jdk: openjdk7
-os:
-  - linux
+    - jdk: openjdk8
 cache:
   directories:
     - $HOME/.gradle/caches/
     - $HOME/.gradle/wrapper/
-before_install:
-  - git config --global user.email "travis@connortumbleson.com"
-  - git config --global user.name "Travis CI Bot"
-  - sudo apt-get update -qq
-  - sudo apt-get install -qq libstdc++6:i386 lib32z1 expect
+install: ./gradlew build
 script: ./gradlew build shadowJar proguard
 branches:
   only: