Add rawboxscore.xml to stats retrieval, fixes #30

[ajbowler]

This adds the data retrieved from rawboxscore.xml to player_stats and team_stats. The data is mostly the same but rawboxscore.xml contains the groundouts and flyouts for each pitcher, go and ao respectively.

Why MLB decided it was worth having two XMLs for the box score I'll never know.

Would appreciate code reviews, since I'm not a Python expert.

• Crosscheck Away batting? #57 and see if it's still an issue. If it requires a larger fix, will be done outside of this PR.
• Log new issue for stats.py getting really big. The team stats and player stats can have their own files.

[ajbowler]

The existing master build is failing so let me know what you want me to change based on build results.

[panzarino]

@ajbowler The build is failing because of a different issue, nothing that you have done wrong. Looks pretty good to me, I'll review it more closely soon and then merge. By chance, did you also fix #57 in this too?

[ajbowler]

I haven't checked #57 yet, I'll do that as part of this PR. Adding a checklist to the OP

[ajbowler]

#57 was a small change, so I added it as part of this PR. Would appreciate not squashing these since they're separate issues.

[ajbowler]

Also logged #59

[panzarino]

@ajbowler Thanks for fixing #57, just a lazy mistake when I was refactoring the method. Merging now, I'm aiming for another release by this weekend that should fix some errors (including the broken builds) and implement this new feature.