add storyboard support
add storyboard support

rainkong/EFCircularSlider,matthewyan/EFCircularSlider,SatoTakeshiX/EFCircularSlider,AlexanderMazaletskiy/EFCircularSlider,eliotfowler/EFCircularSlider,glt3953/EFCircularSlider-glt3953,sidorov-panda/EFCircularSlider,neonaldo/EFCircularSlider,nagyistoce/EFCircularSlider,DmitryNek/EFCircularSlider