https://0xproject.com/docs/0xjs#installation
https://github.com/MetaMask/provider-engine
https://github.com/ethereum/wiki/wiki/JavaScript-API
https://0xproject.com/wiki#Infura-Setup-Guide
https://0xproject.com/wiki#Web3-Provider-Explained
https://github.com/MetaMask/faq/blob/master/detecting_metamask.md