Reduce haproxy refresh handlers to 1

We had handlers for reload and restart, and sometimes both would happen
in quick succession and seemingly cause issues. Reduce them down to just
restart and call it good.
Merge pull request #693 from blueboxgroup/cleanup-haproxy-notices

Reduce haproxy refresh handlers to 1
Reload instead of restart haproxy

Since haproxy needs to be alive for the entirety of a client session,
use the reload functionality. It'll create a new process with new
settings but leave the old process in place until the existing sessions
finish up.
Ensure haproxy service gets enabled

This used to be a side effect of a handler, which is lame. So now it's
an explicit task. We want to flush handlers before the task though to
prevent the task starting the service and then the handler restarting it
immediately after.
Merge pull request #696 from blueboxgroup/reload-not-restart

Reload haproxy instead of restarting it
Only create a venv when in jenkins

The venv can get dirty between runs, it's best to start with a clean
one when in jenkins.

namespaceing happens via the BUILD_ID variable that jenkins inserts. Our
jenkins build is configured to rebuild the workspace each time which
would take care of cleaning out older builds (although that does prevent
concurrent runs on the same slave as the workspace would get cleaned out
from another run).
Drop pep8

pep8 and ansible don't mix at this point, so drop it from being tested.