Don't install autoscale_cloudcafe test

We can just use PYTHONPATH and it works equally well but faster.
Use GIT_SHA for otter and cloudcafe images

Otherwise another build could come through and we wouldn't be testing
with the version we think we are
Change cassandra CMD syntax

There's a bug with the ["exec", "arg"] syntax currently that causes
zombie processes with Java apps that don't shut down correctly. The
other syntax doesn't have this problem.
Change cloudcafe runner to support optional args

We want to run more than just the functional tests with cloudcafe so we
should support arbitrary arguments.
Write cloudcafe config in more reasonable way

Doing sed parsing of a config sucks when it's already a standard format
(ConfigParser/ini). This way we can also avoid passing passwords as
environment variables that are readable.
Make pathing better in update_cc_config
Use update_cc_config script in runner

This creates the config and puts it in the container during the build
rather than hopefully getting it right when we spin up the container. It
also keeps us from having to expose passwords in `ps aux` during
runtime.