Outside imports

[mwufi]

Motivation

This allows NFT storefront code to be imported outside of this repo!

The contracts package is intentionally small - rather than relying on emulator (like the test package here), we only make it so that it can load up the Cadence files. Then, the emulator will decide what to do with them.

Test plan

Test loading of contracts make test in the lib/go/contracts directory

Existing tests (in lib/go/test) make test in the lib/go/test directory