change var for current month index. add prop for customizing day headings
change var for current month index. add prop for customizing day headings

christopherdro/react-native-calendar,hyb175/react-native-calendar,christopherdro/react-native-calendar,samcorcos/react-native-calendar,samcorcos/react-native-calendar,christopherdro/react-native-calendar,hyb175/react-native-calendar,hyb175/react-native-calendar,samcorcos/react-native-calendar