Worker intercepts browser-server bundle (and initial HTML request)

[t-mullen]

I noticed when experimenting with no prefix (a "/" prefix) that the worker can intercept the browser-server bundle itself, as well as the initial HTML request. This makes the worker unable to respond (since it's waiting on the script it's trying to load).

I think this could be solved by adding an option to specify certain paths (for example /bundle.js and /index.html) that the worker should not intercept.

Not needing a prefix would be extremely useful for drop-in lazy loading, since no HTML refactoring would be required.

[mafintosh]

Great idea. Will free to send me a PR :)