Fix missing promisify in disconnect.js, add flow
Fix missing promisify in disconnect.js, add flow

devshackio/react-native-firestack,sraka1/react-native-firestack,devshackio/react-native-firestack,devshackio/react-native-firestack,devshackio/react-native-firestack,sraka1/react-native-firestack,sraka1/react-native-firestack,sraka1/react-native-firestack