Updated get_rate_limit_status to return remaning API calls for statuses on user_timeline.

WIP/BUG: my if/else statements that check get_rate_limit_status did not work as expected. api object printed 'Max retries reached. Sleeping for: 381' instead of proceeding to else statement.
Also, data was not json serializable. Program made a bunch of API calls before trying to save info in json file, so error came after many API calls were already made.
Added column for URL to Status class
Working on Twitter API rate limit problem - how to stop my program before hitting rate limit.

 - removed wait_on_rate_limit params from api auth in tw_api, because I want to handle rate limits myself
 - in seed.py, rewrote get_rate_limit_status function to include a while loop that checks every 900/180 seconds. Moved 900/180 to TIME_TO_WAIT variable on Devney's advice, so I can control variable numbers from a centralized location (top of file)
 - Made while loop with TIME_TO_WAIT because I realized that checking my api rate limit after every single status request was what caused me to hit twitter's API limit so quickly.
 - WIP - will get rid of the while loop, will replace with my own tracking/counting function
Change seed.py to check rate limit while processsing statuses and writing to file.

write_to_file no longer waits for entire status list to be aggregated before writing to file, since errors would cause all those API calls to be in vain.
Uses if/else statement to check whether a counter, n, is less than rate limit.
Created python files for developing my program beyond 'proof of concept' stage.

friends.py creates User and Status objects that have customized functions associated with them.
score.py will score tweets for political content.
Added a few details to class outlines in friends.py.
Enable basic functionality of friends.py by initializing api, adding code to get_friends and hydrate_users

Re-add in code for initializing API class instance.
Try/except to get friend_ids
WIP getting friend_ids to paginate in order to use hydrate_users with 100 user ids at a time.