Revert to drupal/rdf_ui 1.x-dev version (drupal-composer#4)

* ISSUE-513

Fixes Drupal 8.1.x compatibility issue with drupal/rdf_ui by setting
version fixed to 1.x-dev

* Lock package versions to stuff we know work

Author: DiegoPino

composer.json

@@ -24,7 +24,7 @@
         "drush/drush": "~8.0",
         "drupal/console": "~1.0",
         "drupal/devel": "^1.0@beta",
-        "drupal/rdfui": "^1.0@beta",
+        "drupal/rdfui": "1.x-dev",
         "drupal/restui": "^1.13",
         "drupal/media_entity": "^1.6",
         "drupal/media_entity_image": "^1.2",