Remove path-exists

This package trivially wraps core node.js functionality. Let's do
without it.

bin/clean.js

@@ -5,9 +5,9 @@
  * Useful for developers.
  */
 
+var fs = require('fs')
 var os = require('os')
 var path = require('path')
-var pathExists = require('path-exists')
 var rimraf = require('rimraf')
 
 var config = require('../config')
@@ -15,7 +15,12 @@ var handlers = require('../main/handlers')
 
 rimraf.sync(config.CONFIG_PATH)
 
-var tmpPath = path.join(pathExists.sync('/tmp') ? '/tmp' : os.tmpDir(), 'webtorrent')
+var tmpPath
+try {
+  tmpPath = path.join(fs.statSync('/tmp') && '/tmp', 'webtorrent')
+} catch (err) {
+  tmpPath = path.join(os.tmpDir(), 'webtorrent')
+}
 rimraf.sync(tmpPath)
 
 // Uninstall .torrent file and magnet link handlers