Shorten up UIColor creation

UIColorExtension.swift

import UIKit
extension UIColor {
    class func rgb(_ red: Int, _ green: Int, _ blue: Int) -> UIColor {
        return UIColor.rgba(red,green,blue,1.0)
    }
    class func rgba(_ red: Int, _ green: Int, _ blue: Int, _ alpha: Float) -> UIColor {
        return UIColor.init(colorLiteralRed: Float(red)/255.0, green: Float(green)/255.0, blue: Float(blue)/255.0, alpha:alpha)
    }
}

//example
let green = UIColor.rgba(139,195,74,1.0)
let green = UIColor.rgb(139,195,74)