yev-kanivets#95. Updated .travis.yml.

Author: Evgenii Kanivets

.travis.yml

@@ -3,17 +3,17 @@ jdk: oraclejdk8
 android:
   components:
     # The BuildTools version used by your project
-    - build-tools-26.0.2
+    - build-tools-27.0.3
 
     # The SDK version used to compile your project
     - android-21
-    - android-26
+    - android-27
 
     # Additional components
     - extra-google-google_play_services
     - extra-google-m2repository
     - extra-android-m2repository
-    - addon-google_apis-google-26
+    - addon-google_apis-google-27
 
     # Specify at least one system image,
     # if you need to run emulator(s) during your tests