Fix buildpack permission issue for Heroku

[Macleykun]

Now if users would deploy from AvaIre, they wouldn't have this issue (b/c the last run buildpack doesn't have this change). However users who do use the official latest one for the website repo, do notice this problem.

I didn't include any remove stuff here, b/c i'm not sure which files/folder can be deleted to safe space (and improve boot time slightly). Because this repo is still in beta.

However if you do wanna point out what can be removed, this is the current list of stuff that i'm not sure can be removed:

-rw------- .editorconfig
drwx------ .git
-rw------- .gitattributes
drwx------ .github
-rw------- .gitignore
drwx------ .profile.d
-rw------- LICENSE.md
-rw------- Procfile
-rw------- README.md
drwx------ app
-rw------- artisan
drwx------ backgrounds
drwx------ bootstrap
-rw------- buildpack-run.sh
-rw------- composer.json
-rw------- composer.lock
drwx------ config
drwx------ database
drwx------ node_modules
-rw------- package.json
-rw------- phpunit.xml
drwx------ resources
drwx------ routes
-rw------- server.php
drwx------ storage
drwx------ tests
drwx------ vendor
-rw------- webpack.mix.js
-rw------- yarn.lock

For the record, i'm talking about removing files that aren't needed to RUN.