Fixes #267

• Refactored for Pep-8 & Pep-287
• Updated imports for Pep-8 (Standard Library first, 3rd party second, our app 3rd & Alphabetical for each section)
• Replaced ALL_CAPS variables
• Switched unnecessary self variables to function variables
• (Fixed?) Changed localized graph to actually query the session_id instead of giving the Sessions object a quiz_uuid to query by
• Moved test ontology creation outside of the feed & into the app config (this doesn't need to be done individually per user)
• Added dependency injection for the class instead of declaring other classes inside
• (Probably?) Significantly faster since this removes a pass through the ontology. Need to see test results.
• Removed num_feed_cards variable that was being passed through 3 functions and added it directly to function where used

In a separate PR, we need to figure out if the localized graph is doing what it is supposed to do.