Implement basic NBA calls

Add support for NBA teams, schedules and rosters

Add game summary functionality

Add players to nba teams and remove nba team_roster

Allow for different api_keys for different sports

Update README to reflect new api key format

Correct api_key retrieval in specs
Merge pull request #26 from trdinich/nba_basics

Implement basic NBA calls
Merge remote-tracking branch 'upstream/master'

Conflicts:
	spec/spec_helper.rb
Merge branch 'master' of https://github.com/trdinich/sports_data_api