modified README with CocoaPod instructions
modified README with CocoaPod instructions

W2N-git/Calendar,arnaudWasappli/Calendar,patrickHelmedica/Calendar,kriskelly/Calendar,kriskelly/Calendar,W2N-git/Calendar,jumartin/Calendar,Sol88/Calendar,bsdsoftware/Calendar,bsdsoftware/Calendar,george-zergy/Calendar,norary3/DewDateCalendar,norary3/DewDateCalendar