Currently, http://buildbot.python.org/all/buildslaves/ware-docs
buildbot is only run as post-commit. For example, bpo-29521 (PR#41)
introduced two warnings, unnotified by the Travis CI docs job.
Modify the docs job to run toosl/rstlint.py.
Fix also the two minor warnings which causes the buildbot slave to
fail.
If the IRC notification is stored in plaintext, then anyone who forks
the repository and also adds it to travis will send notifications to
the IRC channel for their fork by default. Since the secure variable
is encrypted using a repository specific key, this will only work when
it is being built using the correct repository.