update card pulseColor to allow for optional pulse

Source/MaterialButton.swift

@@ -133,7 +133,7 @@ public class MaterialButton : UIButton {
 		pulseView = UIView(frame: CGRectMake(0, 0, bounds.height, bounds.height))
 		pulseView!.layer.cornerRadius = bounds.height / 2
 		pulseView!.center = (touches.first as! UITouch).locationInView(self)
-		pulseView!.backgroundColor = pulseColor?.colorWithAlphaComponent(0.5)
+		pulseView!.backgroundColor = pulseColor?.colorWithAlphaComponent(0.3)
 		backgroundColorView.addSubview(pulseView!)
 	}
 	

Source/MaterialCardView.swift

@@ -49,7 +49,7 @@ public class MaterialCardView : UIView {
 	/**
 		:name:	pulseColor
 	*/
-	public var pulseColor: UIColor = MaterialTheme.blueGrey.lighten3
+	public var pulseColor: UIColor? = MaterialTheme.blueGrey.lighten3
 	
 	/**
 		:name:	init
@@ -151,7 +151,7 @@ public class MaterialCardView : UIView {
 		pulseView = UIView(frame: CGRectMake(0, 0, width, width))
 		pulseView!.layer.cornerRadius = width / 2
 		pulseView!.center = (touches.first as! UITouch).locationInView(self)
-		pulseView!.backgroundColor = pulseColor.colorWithAlphaComponent(0.3)
+		pulseView!.backgroundColor = pulseColor?.colorWithAlphaComponent(0.3)
 		addSubview(pulseViewContainer)
 		Layout.expandToParent(self, child: pulseViewContainer)
 		pulseViewContainer.addSubview(pulseView!)