Fix the section name in CONTRIBUTING.rst

The name of the section 'if you'are developer...' has changed
in the wiki. This commit updates it to correctly refer to
the good section.

Change-Id: I76767250b45e2550ac1601349a562a7641d41fc3
Remove zmq-receiver from setup.cfg

In commit 1a91aac we removed the zmq-receiver script (in favor of
oslo-messaging-zmq-receiver) but forgot to remove the entry from
setup.cfg.

Closes-Bug: #1279739
Change-Id: Icd08a5b28daee7234abd24ba502c56cc00abcb8c
Merge "Remove zmq-receiver from setup.cfg"
Merge "Fix the section name in CONTRIBUTING.rst"