Remove mkdirp dependency

Replace usage of mkdirp with fs-extra.mkdirp and remove the mkdirp
dependency and the unused mkdirp-promise dependency.

lib/npmPostinstall.js

@@ -1,12 +1,11 @@
-var mkdirp = require("mkdirp");
 var http = require('http');
 var https = require('https');
-var fs = require('fs');
+var fs = require('fs-extra');
 
 
 function makeDirectory(path){
 	return new Promise((resolve, reject) => {
-		mkdirp(path, function(err){
+		fs.mkdirp(path, function(err){
 			if(err){
 				console.error("Unable to mkdirp "+path);
 				console.error(err);

package.json

@@ -53,8 +53,6 @@
     "lib": "file:./lib",
     "luamin": "^1.0.4",
     "minimist": "^1.2.0",
-    "mkdirp": "^0.5.1",
-    "mkdirp-promise": "^5.0.1",
     "moment": "^2.22.2",
     "needle": "^2.4.0",
     "node-factorio-api": "^0.3.8",