Removed some dependencies that were failing to build

[phaux]

I don't understand what was the purpose of these libs:

• pathwatcher wasn't even used anywhere and was causing installation errors described in #2. I replaced the pathwatcher.write call with node.js fs.writeFileSync.
• fuzzaldrin: Filtering suggestions is not needed because Racer is responsible for this.

[edubkendo]

pathwatcher is used here: https://github.com/edubkendo/atom-racer/blob/master/lib/racer-client.coffee#L63 . Maybe it needs a version bump?

[alkama]

Hello !

• From what I understood, pathwatcher.File.write() was used to offer privilege escalation. It itself uses fs.writeFileSync. I also think it's cleaner to directly use the fs module since it's probably rare that users can't write in the default temp directory.
• About fuzzaldrin: the current version of atom-racer is asynchronous, but autocomplete-plus has no asynchronous API for now, so we poll for racer's completions independently from the suggestion building (we do it at each keystroke). In this scenario, fuzzaldrin has some chances to actually provide its feature for a hilariously short time :) (between our async polls for candidates).

I'm currently working on a full synchronous version to comply with the current state of autocomplete-plus. For this new version, I indeed did the same kind of choices (I'll probably move to fs too, better keep dependancies to a vital minimum): https://github.com/alkama/atom-racer/compare/wip-synchronous

So, to sum it up, I kind of second the suggested changes, they're pretty harmless anyway.