Fixed bug that kept post point counts from updating
Made DB migrations actually work for more than one migration script
Redid the algorithm... again... this time it keeps track of the order posts appeared when it stores each time frame's posts. That way, when you say 'top 25' you only get 25, ever, even if a post gets more points and floats up above what /used to be/ #25. In my next commit, you'd get that post next week. Also, changed the app to let any hour be set as the delivery hour, instead of only four times of day. The UI still only exposes those times of day, though.
Fixed storing posts for rank 300. Unit tested get_posts().