Use module mkdirp instead of native unix command that doesn't work on Windows

lib/customUtils.js

@@ -1,7 +1,7 @@
 var fs = require('fs')
   , crypto = require('crypto')
   , path = require('path')
-  , childProcess = require('child_process')
+  , mkdirp = require('mkdirp')
   ;
 
 
@@ -13,7 +13,7 @@ function ensureDirectoryExists (dir, cb) {
   var callback = cb || function () {}
     ;
 
-  childProcess.exec('mkdir -p ' + dir.replace(/ /g, '\\ '), function (err) { return callback(err); });
+  mkdirp(dir, function (err) { return callback(err); });
 }
 
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "nedb",
-  "version": "0.7.4",
+  "version": "0.7.5",
   "author": {
     "name": "tldr.io",
     "email": "hello@tldr.io"
@@ -22,7 +22,8 @@
   "dependencies": {
     "async": "~0.2.8",
     "underscore": "~1.4.4",
-    "binary-search-tree": "0.2.3"
+    "binary-search-tree": "0.2.3",
+    "mkdirp": "~0.3.5"
   },
   "devDependencies": {
     "chai": "1.0.x",