Travis fix to clear exceptions.

Build config file is required via repository settings, but config is empty.

.travis.yml

@@ -3,8 +3,8 @@ jdk:
   - oraclejdk8
 #  blacklist
 branches:
-  except:
-    - gh-pages
+  only:
+    - master
 before_cache:
   - rm -f $HOME/.gradle/caches/modules-2/modules-2.lock
 cache: