Compare coala+gitmate with danger

[danger](http://danger.systems/) includes process and code quality automation, integrated with GitHub and other code repository systems.

An example of process automation is requiring PR authors join the organisation.

coala only provides code quality automation with the addition of git commit message checking.
gitmate adds GitHub integration.

coala+gitmate lacks process automation, and is not especially interested in pursuing that goal.

However coala+gitmate does expect to be better at code quality automation than danger.
A comparison on this wiki would be useful to ensure that coala developers acknowledge where open source competitors in this space, like dangar, are out performing coala.

Review the repository wiki and the linked Danger description, then compare coala+gitmate's stated code-quality and commit-message checking with Danger's process automation. Done means a wiki comparison that identifies relevant differences and where Danger outperforms coala+gitmate.

Written by the indexing model from the issue text.