Added gameType and more modifiers

[conrmahr]

• Be able to call gameType in the schedule API with additional modifiers.

• Be able to call all games without filtering by one team with teamId.

• Tested with the following code

nhl.games.games({ date: '2019-05-04', gameType: 'P' }).then(data => {
	const playoffs = data
	console.log(playoffs)
})

[conrmahr]

nextGame() test fails because Buffalo has no schedule games to play. 😁