Add more control

[abdallaemadeldin]

Really it's an amazing package i'm a big fan of it. but you need to make some enhancement like:-

• you can make me change your component colors without make custom view.
• support multi notifications.
• make more than one theme and let user choose witch one to use.
• on single notification make a theme, and on multi use another theme.

[abdallaemadeldin]

@danielholmes @taixw2 @carsonwah @tozaicevas