Add first pass at solving silent/wrong failures

When github doesn't return a patch lintreview should not post that the
review passed when it actually didn't do a review.

Refs #5
Add fixture that includes a 'rename' and blob add.

Sometimes github renames show up as adds with no patch content. Add
a test file for this case. These files should be skipped when doing
a review.

Refs #5
Another attempt at fixing issues with big changes/no diff changes.

Tests & testing are still needed.
Add and reorganize tests.

Add missing tests and re-organize existing ones to be in the right
classes. Some of the test for Problems() was in the Review() test class.
Add fixture file for diff with removed files.
Add tests for deleted/renamed/modified blobs

Ignore files that match the following conditions:

- Deleted files
- Modified blobs
- Added files with no patches.

Refs #5