Add support for ethers.js-style contract abstraction

[pcowgill]

No description provided.

[pcowgill]

Twitter conversation about how this could be implemented

[ylv-io]

Hey @pcowgill. Things are looking promising for ethers.js. I'll keep posting updates to this issue.

[frangio]

What would be the scope of this?

We clearly would allow choosing ethers.js contract abstractions, by specifying contracts: 'ether' in the config.

Additionally, I suppose we would export a preconfigured ethers.js provider? One issue with that is that we currently export a provider that is a web3.js provider so we have to either give the ethers.js provider export a new name, or allow the user to choose the provider type (though this is super weird because they're not the same thing conceptually).

[pcowgill]

@frangio I think it's a good idea to give the ethers export a different name, especially since ethers has separate notions of signer and provider - I wish web3.js did too. When you add it, maybe make a breaking change to call the existing provider web3Provider?