Close a PR with `pulls close`

Signed-off-by: Solomon Hykes <solomon@docker.com>
Add a comment when taking an PR

The comment format is `#assignee=<USER>`

Signed-Off-By: Solomon Hykes <solomon@docker.com>
remove filters from pulls
Merge pull request #110 from shykes/pulls-close
Merge pull request #109 from shykes/pulls-take-comment
Merge pull request #101 from dotcloud/remove_filters
Fix reviews when rel to the repo root
Use username instead of email for reviewers
Merge pull request #114 from crosbymichael/get-toplevel

Get toplevel
Disable coloring if stdout is not a terminal

Signed-off-by: Solomon Hykes <solomon@docker.com>

This allows piping and redirecting the output of `pulls` without mixing
in term control characters garbage.