ABI in @machinomy/contracts incompatible with mainnet contract

[kincaidoneil]

The bytecode in the Unidirectional contract artifact begins "0x608..." By contrast, the mainnet contract at 0x08e4f70109ccc5135f50cc359d24cb7686247df4 uses a different bytecode (beginning with "0x606...") incompatible with the ABI in that artifact file. However, the artifact file references that mainnet contract under "networks" despite it being incompatible with the ABI in the same file.

Using an older version of the artifact fixes the issue for mainnet.