Create .travis.yml (#21)

I think I need to merge this into master to get Travis the first time.

Author: jophde

.travis.yml

@@ -0,0 +1,38 @@
+language: android
+android:
+  components:
+  - platform-tools
+  - tools
+  
+  - build-tools-24.0.3
+  - android-24
+  
+  - extra-google-m2repository
+  - extra-android-m2repository
+  
+  - sys-img-x86-android-24
+  - sys-img-x86-android-23
+  - sys-img-x86-android-22
+  - sys-img-x86-android-21
+  - sys-img-x86-android-20
+  - sys-img-x86-android-19
+  - sys-img-x86-android-18
+  - sys-img-x86-android-17
+  - sys-img-x86-android-16
+  - sys-img-x86-android-15
+  - sys-img-x86-android-10
+  
+jdk:
+  - oraclejdk8
+  - oraclejdk7
+  - openjdk6
+  - openjdk7
+  
+before_cache:
+  - rm -f $HOME/.gradle/caches/modules-2/modules-2.lock
+  cache:
+    directories:
+      - $HOME/.gradle/caches/
+      - $HOME/.gradle/wrapper/
+      
+script: ./gradlew testAllModules