minor fixes

[evgeniuz]

• removed bin configuration from package.json: this package doesn't provide binary file, so it causes errors on installation;
• fixed parameter passed to combineSource recurrent call: it's called fileRoot, not rootpath now.

[yann300]

@0mkara what should we do with this PR? Is this still valid?

[0mkara]

No. This PR becomes invalid as we are not using combineSource() anymore. Here is the new resolve() mechanism.

https://github.com/ethereum/remix/blob/master/remix-url-resolver/src/resolve.ts#L114