Improve Emoji detection in commit messages
Improve Emoji detection in commit messages

This changes our Danger integration so that it is smarter about
detecting GitLab emoji in commit messages. This is done using a two step
process:

1. We use the old regular expression to determine if a commit message
   _might_ include an emoji.

2. If this regular expression matches, we then check for all existing
   emoji names in the commit message. This might be a wee bit expensive,
   but because we couple it with the previous step it should be rarely
   executed.

This ensures we don't trigger an error when a commit message includes
text such as `:foo:bar:`, which is not a valid Emoji.

Fixes https://gitlab.com/gitlab-org/release/framework/issues/15

stoplightio/gitlabhq,axilleas/gitlabhq,mmkassem/gitlabhq,iiet/iiet-git,stoplightio/gitlabhq,mmkassem/gitlabhq,dreampet/gitlab,iiet/iiet-git,dreampet/gitlab,mmkassem/gitlabhq,axilleas/gitlabhq,iiet/iiet-git,mmkassem/gitlabhq,axilleas/gitlabhq,dreampet/gitlab,stoplightio/gitlabhq,axilleas/gitlabhq,dreampet/gitlab,iiet/iiet-git,stoplightio/gitlabhq