Whitelist master for after-merge build to avoid long travis build queue (#362)

Author: alexsavulescu

.travis.yml

@@ -190,6 +190,13 @@ after_success:
     fi
 
 
+#=============================================================================
+# Whitelist master branch to run Travis CI with it after merge
+#=============================================================================
+branches:
+  only:
+    - master
+
 #=============================================================================
 # Documentation deployment
 #=============================================================================