Don't build Python 3 versions of Celery and deps.
Remove a stray space from python-amqp.spec
Add mock so we can build without a running broker
Fix the doc versions to be 2.4.0.
Configure PYTHONIOENCODING to be UTF-8 for all of our celery daemons.

Also, I happened to notice that our Celery beat process wasn't logging
to its log file, so I fixed that as well.
Merge pull request #785 from pulp/barnabycourt-enable-jenkins-build

Add mock so we can build without a running broker
Merge branch 'rbarlow-no_python_3_in_deps' into distributed-tasks
Merge branch 'rbarlow-doc_versions' into distributed-tasks
Merge branch 'rbarlow-celery_io_encoding' into distributed-tasks
Update for changes from PR
Merge branch 'distributed-tasks' into barnabycourt-doc-update