Update dependency @react-native-community/cli to v2.8.3

Thalia Technicie
2019-08-03T18:51:23+02:00

This MR contains the following updates: | Package | Type | Update | Change | |---|---|---|---| | [@react-native-community/cli](https://github.com/react-native-community/react-native-cli) | dependencies | minor | [`2.4.3` -> `2.8.3`](htt...

@react-native-community/cli | dependencies | minor | 2.4.3 -> 2.8.3