docs(contributing): split out DCO
feat(client): add --app option to apps:run

All of the other apps commands have a --app option. This commit
introduces that option to the apps:run command as well.

fixes #722
Merge pull request #887 from deis/split-dco

docs(contributing): split out DCO
Merge pull request #899 from deis/722-app-run

feat(client): add --app option to apps:run
chore(controller): update celery to 3.1.11

http://docs.celeryproject.org/en/latest/changelog.html#version-3-1-11
chore(controller): update django-allauth to 0.16.1

https://github.com/pennersr/django-allauth/compare/0.15.0...0.16.1
chore(controller): update django-guardian to 1.2.0

http://django-guardian.readthedocs.org/en/v1.2/develop/changes.html
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 gevent to 1.0.1

https://github.com/surfly/gevent/blob/1.0.x/changelog.rst#release-101-apr-30-2014
chore(controller): update pyyaml to 3.11

http://pyyaml.org/wiki/PyYAML#History
chore(controller): update paramiko to 1.13.0

https://github.com/paramiko/paramiko/compare/v1.12.1...v1.13.0
chore(controller): install new pip from bootstrap.pypa.io endpoint

https://github.com/pypa/pip/compare/1.5.4...1.5.5