Write a loader for our Git log file

[andymeneely]

The loader should minimally pick up the following attributes from chromium-gitlog.txt: For Commit Model:

• Commit hash
• Parent commit hash
• Author email
• Message
• Code review (s) (this might be hard to parse in some situations - for example when they quote another code review, pull ID)
• Filepaths (by way of the CommitFiles model)
• BUG= field (should be an int)
• R=field (reviewers)
• TEST field (should be text field)
• SVN revision (an int, pull ID)

For CommitFiles Model:

• Filepaths (text type)
• Commit (relation back to Commit)

Don't bother with the churn data - we'll use our own scripts to collect churn if we need it (but we may not even need it)

This also means creating two models: Commit and CommitFiles.

Also: take ~5 commits from the chromium-gitlog.txt on our data repo and commit it to this repo as our test data under test/data/

[andymeneely]

Use the new Loader conventions, as seen here:

https://github.com/andymeneely/chromium-history/blob/1dd65f2cef51efc38faa066404a7027bd6c1d042/lib/chromium_history/loaders/code_review_loader.rb

Create a new GitLoader

[andymeneely]

Check out this commit, which is pretty similar in nature: 1dd65f2cef51efc38faa066404a7027bd6c1d042