Remove check_uptodate.sh check from tox.ini

This removes the check_uptodate.sh test from the py2* tox envs and
run_tests.sh. It also syncs the sample config one last time to document
some new options available to users running with the newer
oslo.messaging versions.

Change-Id: I6107b996d5da808c3222696a9549ee06c22f80b9
Closes-bug: #1399085
Merge "Remove check_uptodate.sh check from tox.ini" into stable/juno