Javascript API

#8 Create an API for interacting with the contracts
#16 Create API wrapper for truffle contract

ERC721 HTLCs, travis, linting

HTLCs for ERC721 are now possible thanks to the kaleido pull request #13

Additionally ethlint/solium linting and travis builds are now setup in the project.

Solidity 0.5 upgrade

#9 upgraded 0.5.* solidity and new truffle
#3 etherscan source verified and published

Solidity upgrade and test fixes

Upgraded to 0.4.24 plus prepared for 0.5.0.
Add revert error messages.
Fixed intermittently failing tests.

Deployed to Kovan and Ropsten.