Bug: Skaters and goalies tables are getting duplicate data entered.

[MattRWallace]

Skaters and goalies databases seem to be duplicating entries that then need to be dropped during the training.

Determine why/how the duplication is happening, then remove the logic that drops the duplicates.

NHLPredictor/src/nhl_predictor/model/summarizers/average_player_summarizer.py

Line 117 in fcdf75e

skaters_db = skaters_db.groupby([Keys.game_id, Keys.player_id]).first().reset_index()