Doesn't support landscape mode #3

When showing the SCLAlert component in landscape mode, I get an error:

Exception thrown while executing UI block: Supported orientations has no common orientation with the application, and [RCTModalHostViewController shouldAutorotate] is returning YES

As per this thread the solution is to add supportedOrientations={['portrait', 'landscape', 'landscape-left', 'landscape-right']} (as well as to modify styles to make it look good). Could someone please PR this?