feat(router): configurable gzip settings

Fixes #884
chore(controller): update djangorestframework to 2.3.13

https://github.com/tomchristie/django-rest-framework/compare/2.3.12...2.3.13
chore(controller): update celery to 3.1.11

http://docs.celeryproject.org/en/latest/changelog.html#version-3-1-11
chore(controller): update redis to 2.9.1

https://github.com/andymccurdy/redis-py/compare/2.8.0...2.9.1
refactor(controller): removed unused ssh.py and its dependencies

We weren't using paramiko or pycrypto any longer.
fix(test): remove `-K` ssh-add option that isn't available on Linux

The Mac OS X version of `ssh-add` has the `-K` flag to update the
passphrase, but `ssh-add` in Ubuntu 14.04 LTS does not.
Merge pull request #971 from deis/integration-linux-fix

fix(test): remove `-K` ssh-add option that isn't available on Linux
Merge pull request #965 from johanneswuerbach/gzip-router

feat(router): configurable gzip settings
Merge pull request #943 from deis/python-updates

chore(controller): update celery, djangorestframework, redis
feat(client): add apps:rename command

This allows users to modify their app names after having created
one.

There was a previous test in api/tests/test_app that checked
to ensure that the PATCH method was not allowed, so I repurposed
it to test appname changes.

The API call to modify app names is:

    PATCH /api/apps/{appname} {new_name}

Which will return HTTP status 200, and the endpoint is no longer
available. You will be able to reach the app at /api/apps/{new_name}
moving forward.

TESTING: Since this affects practically every aspect of app
management, running the integration test suite is recommended:

    $ vagrant up
    $ make pull
    $ cd test
    $ bundle exec rake

fixes #475