Add unit tests for include_links in get_services()
Add integration tests for Service.recreate_containers() with keep_old
Add integration tests for Project.up() w/ start_links and keep_old
Write tests for --no-links changes to `fig up`
Re-add missing import for patch
Write integration tests on new `fig run` linking behaviour
Write integration tests for `--keep-old` in the CLI
Remove unused: from __future__ import unicode_literals.

This is not being used and it confuses the Command class. Rather
than try to fix the Command class, I've taken the pragmatic
approach and removed the trigger that confuses it.