added missing label placeholder for artist in HomeViewController (Main.storyboard)
beginning implementation of DHNetworkManager
stubbed out implementation for searchForTerm:completion:failure
cleaned up stubbed methods of DHNetworkManager so project builds successfully
implemented searchForTerm:completion:failure
implemented DHNetworkManager, need to test
added XCTest class for DHNetworkManager
added AFNetworking to test target
added unit tests for DHNetworkManager