Rewrite Travis-CI configuration to enable caching

Signed-off-by: Harsh Shandilya <msfjarvis@gmail.com>

.travis.yml

@@ -1,29 +1,31 @@
 language: android
+dist: trusty
+
+jdk:
+  - openjdk8
+
 android:
   components:
-    # Uncomment the lines below if you want to
-    # use the latest revision of Android SDK Tools
     - tools
-    - tools # https://github.com/travis-ci/travis-ci/issues/6040#issuecomment-219367943
-    - platform-tools
-
-    # The BuildTools version used by your project
     - build-tools-28.0.3
-
-    # The SDK version used to compile your project
     - android-28
-
-    # Additional components
-    # - extra-google-google_play_services
-    - extra-google-m2repository
     - extra-android-m2repository
-    # - addon-google_apis-google-19
+  licenses:
+    - ".+"
+
+script:
+  - ./gradlew build check
+
+notifications:
+  email: false
 
-    # Specify at least one system image,
-    # if you need to run emulator(s) during your tests
-    # - sys-img-armeabi-v7a-android-19
-    # - sys-img-x86-android-17
-jdk:
-    - oraclejdk8
 sudo: false
-script: ./gradlew build check
+
+before_cache:
+  - rm -f  $HOME/.gradle/caches/modules-2/modules-2.lock
+  - rm -fr $HOME/.gradle/caches/*/plugin-resolution/
+
+cache:
+  directories:
+    - $HOME/.gradle/caches/
+    - $HOME/.gradle/wrapper/