Make settings_example.py Usable for Local Development

Ideally developers should require as little setup as possible
to get starting working on relengapi. This change will default
the settings to create a sqlite database in the current directory.
Adds default sqlite databases to default settings and example settings.
Merge remote-tracking branch 'pr/127'
Add a BadpennyJobLog table
Add 'app.db.flush_sessions' for testing
add as-yet failing tests
Read from and write to the badpenny logs table
load logs in the frontend
Merge djmitche/build-relengapi:issue130 (PR #137)