Allow the ability to override activeOpacity in CardItem

[davidvuong]

Here: https://github.com/GeekyAnts/NativeBase/blob/master/src/basic/CardItem.js#L8-L28

class CardItem extends Component {
	render() {
		if (this.props.button) {
			return (
				<TouchableOpacity
					ref={c => (this._root = c)}
					{...this.props}
					activeOpacity={this.props.button ? 0.2 : 1}
				>
					{this.props.children}
				</TouchableOpacity>
			);
		} else {
			return (
				<View ref={c => (this._root = c)} {...this.props}>
					{this.props.children}
				</View>
			);
		}
	}
}

When button is specified, you hardcode the activeOpacity to 0.2. Can this be changed so that activeOpacity can be overridden?

[SupriyaKalghatgi]

Fixed with 2.3.6