Merge pull request #30 from wojsmol/patch-1

Move PHP 5.4 tests from `WP_VERSION` `latest` to `5.1`

Author: schlessera

.travis.yml

@@ -71,4 +71,4 @@ jobs:
     - stage: test
       php: 5.4
       dist: precise
-      env: WP_VERSION=latest
+      env: WP_VERSION=5.1