Update dependency react-native-firebase to v5.4.1

Thalia Technicie
2019-05-30T11:16:31+02:00

This MR contains the following updates: | Package | Type | Update | Change | References | |---|---|---|---|---| | react-native-firebase | dependencies | patch | [`5.4.0` -> `5.4.1`](https://diff.intrinsic.com/react-native-firebase/5.4.0...

react-native-firebase | dependencies | patch | 5.4.0 -> 5.4.1 | source