Move the haas.http to an external library.

You now need to install:

    https://github.com/cci-moc/moc-rest

Before doing `pip install -e .`

TODO: need to document this in the README, and possibly automate.
Remove Werkzeug dependency.

We're no longer using this directly. We *should* somehow specify a
dependency on moc-rest (which does depend on Werkzeug), however.
Add info re: moc-rest dependency to README.
Merge pull request #289 from zenhack/use-moc-rest

Move the haas.http to an external library.