Add the ability to specify the parity host

[SeekTheError]

Wrote this PR so I could use cobalt as a full-blown deployer programmatically.

[mirek]

You can use it already by providing Object as provider:

const Web3 = require('web3')
const makeWeb3 = require('@appliedblockchain/cobalt/web3')
const web3 = makeWeb3({
  provider: new Web3.providers.WebsocketProvider('ws://localhost:8546')
})

[mirek]

But yes, it should be smart/convenient to recognize ws://, wss://, http://, https://, ipc:// (file:?)...

[SeekTheError]

@mirek Didn't realize you could pass a provider object...
Anyway I added support for ipc:// urls so I guess it's good enough now? Just let me know.

[mirek]

I think we shouldn't introduce new "host" attribute, just use provider for those values:
if it's ganache string -> start ganache, otherwise pass it directly as is to new Web3(provider) (wss?, https? cases should be handled correctly by web3 itself, same with provider objects)
^wss? -> ws provider
^https? -> http provider
otherwise pass it as is to allow for setting up provider somewhere else.

parity case should be removed.

If you do it we can merge otherwise I should have some time soon to look at it.

[SeekTheError]

@mirek Done, I left a special case for ipc since the autodetect fails for ipc:// like urls

[mirek]

Thanks, feel free to do:

npm version minor
git push
git push --tags