update readme
update readme

iCodesign/ICSPullToRefresh-Swift,dennisrjohn/ICSPullToRefresh.Swift,dennisrjohn/ICSPullToRefresh.Swift,iCodesign/ICSPullToRefresh-Swift,iCodesign/ICSPullToRefresh.Swift,MarvinNazari/ICSPullToRefresh.Swift,iCodesign/ICSPullToRefresh.Swift,MarvinNazari/ICSPullToRefresh.Swift,dennisrjohn/ICSPullToRefresh.Swift