Updated lines metrics to include more file types
Merge branch 'master' of https://github.com/asottile/git-code-debt
Merge branch 'master' of https://github.com/asottile/git-code-debt
Added a new base class for single metrics based off line counts.

Also added a TODO counter.
Merge branch 'master' of https://github.com/asottile/git-code-debt

Conflicts:
	git_code_debt/discovery.py