fix(*): all services ensure valid config file on reload

Closes #1099
Replaces #1626
test(builder): update etcd keys in builder test

The confd templates expected some more etcd keys than were seeded
before. Add those extra keys in.
fix(router): add check command for nginx config

Check for `<no value>` in nginx config, which usually means that
something is wrong with the configuration in etcd.
Merge pull request #1629 from deis/fix/check-config

fix(*): all services ensure valid config file on reload
fix(tests): take a nap after fleet restart
feat(*): add `make test-style` targets

This gives us an opporunity to run code checkers and linters as part
of testing, as we used to on travis-ci.org. By default, unit tests
will check code syntax and style first.
ref(*): clean up Go and Python code for `make test-style`
fix(docs): add client reference for `deis tags`
Merge pull request #1670 from mboersma/deis-tags-autodocs

fix(docs): add client reference for `deis tags`
Merge pull request #1666 from mboersma/1509-make-test-style

feat(*): add `make test-style` targets
chore(CHANGELOG.md): update for v0.11.0
chore(*): update master to v0.12.0
Merge remote-tracking branch 'upstream/master'
docs(client): update with dev CLI binaries and local deis.py suggestion
Merge pull request #1672 from mboersma/update-cli-links

docs(client): update with dev CLI binaries and local deis.py suggestion
fix(contrib/gce): fix accidental typo in GCE generator
Merge pull request #1675 from deis/fix/docs/gce

fix(contrib/gce): fix accidental typo in GCE generator
Merge remote-tracking branch 'upstream/master'
hmm