MaterialDeviceType switch issue

XCode build error: Switch must be exhaustive, consider adding a default clause

Sources/MaterialDevice.swift

@@ -47,7 +47,7 @@ public struct MaterialDevice {
 			return .iPhone
 		case .TV:
 			return .TV
-		case .Unspecified:
+		default:
 			return .Unspecified
 		}
 	}
@@ -76,4 +76,4 @@ public struct MaterialDevice {
 	public static var scale: CGFloat {
 		return UIScreen.mainScreen().scale
 	}
-}
\ No newline at end of file
+}