Revert "Revert "query and show commits by branch""

This reverts commit 7d52a4c4df0addb0b8de22404ceaffb2148721bf.
use query parameter for commit branch
Add build links to Slack notifications
Merge pull request #250 from marksteve/master

Add build links to Slack notifications
Merge pull request #247 from vito/branch-commits

add branch query parameter to commit view