Add defensive stats to NCAAF teams

[ajhodges]

• Added the following properties to a Team:
  opponents_pass_completions
opponents_pass_attempts
opponents_pass_completion_percentage
opponents_pass_yards
opponents_interceptions
opponents_pass_touchdowns
opponents_rush_attempts
opponents_rush_yards
opponents_rush_yards_per_attempt
opponents_rush_touchdowns
opponents_plays
opponents_yards
opponents_turnovers
opponents_fumbles_lost
opponents_yards_per_play
opponents_pass_first_downs
opponents_rush_first_downs
opponents_first_downs_from_penalties
opponents_first_downs
opponents_penalties
opponents_yards_from_penalties
• Added parsing logic for aforementioned fields
• Modified _retrieve_all_teams to merge defensive stats with conference/offensive stats.
• Added unit test assertions for Perdue's 2017 defensive stats

Closes #193

[codecov]

Codecov Report

Merging #194 into master will increase coverage by <.01%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master     #194      +/-   ##
==========================================
+ Coverage   99.97%   99.97%   +<.01%     
==========================================
  Files          43       43              
  Lines        9299     9365      +66     
==========================================
+ Hits         9297     9363      +66     
  Misses          2        2

Impacted Files	Coverage Δ
sportsreference/ncaaf/constants.py	100% <100%> (ø)	⬆️
sportsreference/ncaaf/teams.py	100% <100%> (ø)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8cb38db...77385d6. Read the comment docs.

[roclark]

Absolutely wonderful work @ajhodges! This is incredible and adds a lot of valuable content to the repository! I just added a couple of very minor clarification questions, but otherwise this looks great and I'm happy to merge it! I have another bug I want to sort out with the project, but once complete, I will spin a new release to make sure this gets out for the rest of the community.

Thanks again!

[roclark]

I noticed that your recent commit is now failing the Travis checks... Not really sure what happened since your changes are completely unrelated to the failing test, but I will dive into this and see why this is happening.

[roclark]

On further investigation, master is also failing, so the issue with the tests is definitely not related to your update. I will try and get a fix out to make sure this is passing, but otherwise I have no issue here and am happy to merge it! Thanks again for pushing this out!

[roclark]

Applied a fix and now everything is looking good here, so I will go ahead and merge! Thanks again for the great work! 🥇