Avoid warnings regarding max listeners.

Seeing this:

```
(node) warning: possible EventEmitter memory leak detected. 11 listeners added. Use emitter.setMaxListeners() to increase limit.
Trace
    at EventEmitter.addListener (events.js:160:15)
    at /usr/local/lib/node_modules/proximity/node_modules/fs-watch-tree/lib/tree-watcher.js:74:21
    at /usr/local/lib/node_modules/proximity/node_modules/fs-watch-tree/lib/async.js:15:21
    at /usr/local/lib/node_modules/proximity/node_modules/fs-watch-tree/lib/fs-filtered.js:23:9
    at Object.oncomplete (fs.js:107:15)
```

Upping the max listeners seems to resolve it.
Merge pull request #5 from andyburke/master

Avoid max listener warnings...