Allow fast finish up travis builds

As soon as one part of the build has failed,
the job will be marked as a failure and appear
red in github.

See: http://about.travis-ci.org/blog/2013-11-27-fast-finishing-builds
Move flake8 checks to before_install
Running Python first for flake8
Add `--match v.[0-9]*` to `git describe` (Fix #11727)

In order to prevent non-official tags from causing
server/client version breakage, filter out all non
official-looking tags, i.e. "v.4.4.9"
Match 'gitmatch' configurable
Move to '0.0.0' style tags
Merge pull request #1870 from joshmoore/rebased/dev_4_4/travis-fast-finish

Allow fast finish up travis builds (rebased onto dev_4_4)
Merge pull request #1879 from joshmoore/rebased/dev_4_4/11727-git-describe

Add `--match v.[0-9]*` to `git describe` (rebased onto dev_4_4)