Removed cross-spawn dependency

This might fix the "spawn cmd.exe ENOENT" issue on Windows.

package.json

@@ -125,9 +125,6 @@
     "winston": "^2.2.0",
     "yaml-front-matter": "^3.2.3"
   },
-  "optionalDependencies": {
-    "cross-spawn": "^2.0.0"
-  },
   "activationCommands": {
     "atom-workspace": [
       "atom-beautify:help-debug-editor",

src/beautifiers/beautifier.coffee

@@ -4,12 +4,7 @@ fs = require("fs")
 temp = require("temp").track()
 readFile = Promise.promisify(fs.readFile)
 which = require('which')
-# Get optional dependency cross-spawn
-spawn = null
-try
-  spawn = require('cross-spawn')
-catch err
-  spawn = require('child_process').spawn
+spawn = require('child_process').spawn
 
 module.exports = class Beautifier