Generate a Image filled with given colors, and a hexstring on each section of colors.
##Usage
Swift
let colors = ["#B9E937", "#93E4C1", "#3BAEA0", "#118A7E", "#1F6F78"]
let font = UIFont(name: "Helvetica Bold", size: 12)
let colorImage = getImageWithColor(CGSize(width: 200, height: 300), colors: colors, textFont: font!, textColor: UIColor.whiteColor())