Collect and parse churn data

[andymeneely]

Let's get churn data into the data set for each commit. We have some scripts already from a previous project.

• [x] Update the database schema: commits, some release_filepath metrics
• [ ] Using our interactive churn script from the HTTPD project, collect churn data for each commit.
• [ ] Write a separate loader that loads that into the database, updating the commit models.
• [ ] Write a release filepath populator
• [ ] Write a verify that it was loaded properly
• [ ] Write a verify that it was aggregated properly

[andymeneely]

We'll need to use these scripts:

https://github.com/andymeneely/httpd-history/blob/master/src/main/sh/gitchurn.sh https://github.com/andymeneely/developer-activity-metrics/blob/master/src/main/sh/git-interaction-churn.rb

I actually would love a more robust command line utility that collects interactive churn for each commit.