fix: heroku install text

[ci skip]

npm/install.js

@@ -215,7 +215,7 @@ const tasks = {
 // INSTALL SEQUENCE
 // =====================================================
 
-if (!process.env.IS_HEROKU && !process.env.WIKI_JS_DOCKER) {
+if (!process.env.WIKI_JS_HEROKU && !process.env.WIKI_JS_DOCKER) {
   console.info(colors.yellow(
     ' __    __ _ _    _    _     \n' +
     '/ / /\\ \\ (_) | _(_)  (_)___ \n' +

npm/package.json

@@ -1,6 +1,6 @@
 {
   "name": "wiki.js",
-  "version": "1.0.0-beta.12.1",
+  "version": "1.0.0-beta.12.2",
   "description": "A modern, lightweight and powerful wiki app built on NodeJS, Git and Markdown",
   "main": "install.js",
   "scripts": {