Update TravisCI to explicitly set distribution

Amir Tocker · tocker · commit 01ea9408c2e4 · 2017-07-20T17:50:22.000+03:00
(cherry picked from commit 9d76a98)
diff --git a/.travis.yml b/.travis.yml
@@ -1,4 +1,7 @@
 language: android
+dist: trusty
+sudo: required
+group: edge
 
 android:
   components:
