Filter commits per path on API endpoint /projects/:id/repository/commits
## Description
Use existing code to filter repository commits matching a path through the API.
~"feature proposal"
## Proposal
Add optional parameter `path` to the API endpoint `/projects/:id/repository/commits`.
## Links / references
- http://stackoverflow.com/questions/32424371/is-it-possible-to-get-commits-history-for-one-file-in-gitlab-api
issue