fix travis

.travis.yml

@@ -72,7 +72,8 @@ jobs:
       - VERSION_NUM=${VERSION_NUM#\"} 
       - VERSION_NUM=${VERSION_NUM%\"} 
       - 'echo "VERSION_NUM: $VERSION_NUM"'
-      - 'test -z "$(grep $VERSION_NUM < mkdocs.yml)" && exit 1'
+      - 'cat mkdocs.yml'
+      - 'test -z "$(cat mkdocs.yml | grep $VERSION_NUM)" && exit 1'
 
     # Temporarily disabling browserstack e2e tests. They seem to fail without any reason