Deduped modules don't get included in worker blob #41

This causes an exception at runtime when the missing module is required.

The resolveSources function tries to recursively find all dependencies, but it doesn't know about modules that are deduped, which have an entry in the modules map that looks like this:

"/Users/jhiesey/Projects/node/stream-http/node_modules/inherits/inherits_browser.js": [function(require, module, exports) {
    arguments[4]["/Users/jhiesey/Projects/node/airtap/node_modules/inherits/inherits_browser.js"][0].apply(exports, arguments)
}
, {}]

The module the dedupe entry points to ("/Users/jhiesey/Projects/node/airtap/node_modules/inherits/inherits_browser.js") needs to be included too, but resovleSources doesn't know that, so the dedupe entry throws at runtime.