Added 'test_api' module.
Test: 'players' GET all method
Added 'tests.util' module
Move 'make_player' function to 'tests.util' module
Test: 'player_get_one'
Fix: 'player_get_one'
Test: 'player_create'
Test: 'player_update'
Test: 'player_delete'
Test: 'util.BaseTest'

Add 'util.BaseTest' base class for Test cases. This class clears the
data files after each test.
Test: 'lineup' API tests
Work: Fix 'Lineup.to_dict_full' method
Merge branch 'caleb-api-tests' into caleb