Initial implementation of special flair for monthly top 10 users

This is an initial implementation of the feature requested in #18

This uses the flair['top1'] and flair['top10'] values set in the config.json to add a special CSS class to the month's top earner and a different, special CSS class for the month's top 2-10 earners.

This clears last month's CSS flairs as well as this months, so that only 10 users have the special flairs at any given time.

The update_top_ten_css method only modifies the CSS class of the flair, not the actual value.


This HAS NOT BEEN TESTED. Although the tests pass, I have no real way of testing this without access to DeltaBot.