Update .travis.yml

[ci skip]

.travis.yml

@@ -18,12 +18,7 @@ android:
     - extra-google-m2repository
 
     # The SDK version used to compile your project
-    - android-27
+    - android-26
 
   licenses:
     - '.+'
-  before_script:
-    - echo no | android create avd --force -n test -t android-27 --abi armeabi-v7a
-    - emulator -avd test -no-skin -no-audio -no-window &
-    - android-wait-for-emulator
-    - adb shell input keyevent 82 &