Added padding and borderRadius props for some more basic styling options

[acealone]

Please give it a good look before merging. I am pretty new to React Native and React in general.
This should theoretically add some more style options to the current ones.

[borisevstratov]

Seems like you can use containerStyle property for that, e.g.:

    Toast.show("Toast:test message", {
      duration: Toast.durations.LONG,
      position: Toast.positions.TOP,
      shadow: false,
      animation: true,
      hideOnPress: true,
      delay: 0,
      textColor: "cyan",
      containerStyle: {
        borderRadius: 25,
        padding: 50,
        backgroundColor: "red",
      },
    });