Removing unneeded directives.

docker/build/xqueue/Dockerfile

@@ -2,7 +2,6 @@ FROM edxops/precise-common:latest
 MAINTAINER edxops
 
 USER root
-RUN apt-get update
 ADD . /edx/app/edx_ansible/edx_ansible
 COPY docker/build/xqueue/ansible_overrides.yml /
 WORKDIR /edx/app/edx_ansible/edx_ansible/docker/plays

docker/plays/xqueue.yml

@@ -3,6 +3,5 @@
   sudo: True
   gather_facts: True
   roles:
-    - common_vars
     - docker
     - xqueue