Include Total Points in player_stats return

[DMcP89]

I have updated the player_stats command to leverage the League resource from the Yahoo API instead of the Player resource. This allows us to return the total points and all the stats details. There are a few other benefits IMO:

• Makes the library more predictable as the league class is now using the league resource instead of an edge case where it uses the player resource
• We are only gaining data here the league /stats endpoint returns the same values as the players /stats endpoint
• Allows us to simplify the mock for player_stats