Update .travis.yml

Author: jd-alexander

.travis.yml

@@ -1,3 +1,6 @@
+before_install:
+ - chmod +x gradlew
+
 language: android
 android:
   components:
@@ -28,4 +31,4 @@ android:
     # 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
+    #- sys-img-x86-android-17