Use travis lts
diff --git a/.travis.yml b/.travis.yml
index 989e5da..0706571 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,5 +1,6 @@
 # https://cloud.google.com/solutions/continuous-delivery-with-travis-ci
 language: android
+group: travis_lts
 cache:
   directories:
   - "$HOME/.m2"