Require fwup 1.5 or later
Require fwup 1.5 or later

While most users won't need 1.5, updating to it brings in fixes and
includes GPT and SOURCE_DATA_EPOCH support which will be nice to expect.

Fwup 1.5 was released November 16, 2019.

nerves-project/nerves,nerves-project/nerves