Update dependency react-native-firebase to v5.5.4

Thalia Technicie
2019-06-30T11:27:47+02:00

This MR contains the following updates: | Package | Type | Update | Change | |---|---|---|---| | [react-native-firebase](https://github.com/invertase/react-native-firebase) | dependencies | patch | [`5.5.3` -> `5.5.4`](https://renovateb...