Issue title: Can't run learnyounode
 Issue body: Hi, I cannot run learnyounode. I tried reinstalling node lts version. I can't install it globally strangely with g-. My code is below. I can see the node_module folder and the learnyounode terminal app in it in my user folder. I would appreciate any help! Thanks!

acintosh:~ user$ npm install learnyounode
ronald88@example.net node_modules/learnyounode
├── ronald88@example.net
├── ronald88@example.net
├── ronald88@example.net
├── ronald88@example.net
├── ronald88@example.net (ronald88@example.net)
├── ronald88@example.net (ronald88@example.net)
├── ronald88@example.net (ronald88@example.net)
├── ronald88@example.net (ronald88@example.net, ronald88@example.net)
├── ronald88@example.net (ronald88@example.net)
├── ronald88@example.net (ronald88@example.net, ronald88@example.net)
├── ronald88@example.net (ronald88@example.net, ronald88@example.net, ronald88@example.net)
├── ronald88@example.net (ronald88@example.net)
├── ronald88@example.net (ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net)
├── ronald88@example.net (ronald88@example.net)
└── ronald88@example.net (ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net, ronald88@example.net)
Macintosh:~ user$ learnyounode
-bash: learnyounode: command not found
 Comments: 
 Comment 0: What's the output when you do run it with the `-g` flag?
 Comment 1: What errors do you receive when installing with the `-g` flag?
 Comment 2: Run this on the command line:

./node_modules/learnyounode 

That's where the module gets installed and you must use the path to it when not installing it globally. 
Or you could of course add this to your shell path as well. Then you can just say: learnyounode 

 Comment 3: @leftieFriele Ive got diff path, but it works, thanks! 
 Comment 4: This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

 Comment 5: This issue is being automatically closed due to inactivity. Please feel to re-open.

{'source': 'GithubIssues', 'repo_name_with_owner': 'nodeschool/discussions', 'issue_id': 142083194, 'repo_stars': 604.0}