Merge pull request #1412 from grails/disableTravis

Run Travis builds only for 6.1.x and 7.0.x branches

Author: puneetbehl

.travis.yml

@@ -6,6 +6,10 @@ cache:
     - $HOME/.gradle/caches/
     - $HOME/.gradle/wrapper/
 language: groovy
+branches:
+  only:
+    - 7.0.x
+    - 6.1.x
 jdk:
 - openjdk8
 - openjdk11