Updated README for Swift 1.2 requirements
Updated README for Swift 1.2 requirements

slightair/SwiftGraphics,sdesimone/SwiftGraphics,sdesimone/SwiftGraphics,hejunbinlan/SwiftGraphics,Pretz/SwiftGraphics,hejunbinlan/SwiftGraphics,marinehero/SwiftGraphics,SheffieldKevin/SwiftGraphics,slightair/SwiftGraphics,hejunbinlan/SwiftGraphics,rhcad/SwiftGraphics,Pretz/SwiftGraphics,marinehero/SwiftGraphics,slightair/SwiftGraphics,marinehero/SwiftGraphics,rhcad/SwiftGraphics,hejunbinlan/SwiftGraphics,rhcad/SwiftGraphics,slightair/SwiftGraphics,Pretz/SwiftGraphics,sdesimone/SwiftGraphics,sdesimone/SwiftGraphics,Pretz/SwiftGraphics,marinehero/SwiftGraphics,SheffieldKevin/SwiftGraphics,SheffieldKevin/SwiftGraphics,rhcad/SwiftGraphics