Designing Database / Adding scoring features / Roster splitting

[rjbray915]

Continue adding database fields for Players like batting average and score / game. Begin implementing features for tagging games, like pitches. Roster splitting would be nice to implement, since this is one of our major features compared to our competitors. This will likely spill into the next sprint, since it will be more important to implement tagging features first.

[rjbray915]

Worked with Taylor to add new Models for Inning, Game, Play, AtBat, and Pitch to keep track of scoring and timestamps for tagging. This was put into a separate branch and needs to be tested for Sprint 3. Now we need to link this with the frontend and get tagging going.