Reduce Travis builds

Author: hannesa2

.travis.yml

@@ -15,17 +15,22 @@ android:
     - 'android-sdk-preview-license-.+'
     - 'android-sdk-license-.+'
     - 'google-gdk-license-.+'
+
+branches:
+  only:
+    - master
+
 before_install:
-    # Android SDK installation is a mess, especially with licenses. Not sure if all of this is required, but it works.
-    - echo "$ANDROID_HOME"
-    - mkdir -p "$ANDROID_HOME/licenses"
-    - echo -e "\n8933bad161af4178b1185d1a37fbf41ea5269c55" > "$ANDROID_HOME/licenses/android-sdk-license"
-    - echo -e "\n84831b9409646a918e30573bab4c9c91346d8abd" > "$ANDROID_HOME/licenses/android-sdk-preview-license"
-    - yes | sdkmanager "platforms;android-27"
+  # Android SDK installation is a mess, especially with licenses. Not sure if all of this is required, but it works.
+  - echo "$ANDROID_HOME"
+  - mkdir -p "$ANDROID_HOME/licenses"
+  - echo -e "\n8933bad161af4178b1185d1a37fbf41ea5269c55" > "$ANDROID_HOME/licenses/android-sdk-license"
+  - echo -e "\n84831b9409646a918e30573bab4c9c91346d8abd" > "$ANDROID_HOME/licenses/android-sdk-preview-license"
+  - yes | sdkmanager "platforms;android-27"
 
 script:
-    # build includes lint and test
-    - TERM=dumb ./gradlew build
+  # build includes lint and test
+  - TERM=dumb ./gradlew build
 
 after_failure:
-    - cat **/build/reports/lint-results.xml
+  - cat **/build/reports/lint-results.xml