Update dependency metro-core to v0.54.1

Thalia Technicie
2019-05-30T11:16:32+02:00

This MR contains the following updates: | Package | Type | Update | Change | References | |---|---|---|---|---| | metro-core | dependencies | minor | [`0.51.1` -> `0.54.1`](https://diff.intrinsic.com/metro-core/0.51.1/0.54.1) | [source]...

metro-core | dependencies | minor | 0.51.1 -> 0.54.1 | source