pass host as command line arguments

Currently, require `project/example.com/path/to/file` for matching file.

```
return path.join(baseDir, urlObject.host, urlObject.pathname);
```
- https://github.com/azu/node-cocproxy/blob/ab1461df6add9019c5bca0dca5b28fc427f54e32/lib/local-finder.js#L14

I want to specify `example.com` by command line argument instead of directory.
### UseCase

When Alice is developing in `alice.github.io` and Bob is developing in `bob.github.io`, It it difference `host` between both.
So, I want to use command line argument instead of directory name for specifing `host`.