Express + Consolidate + Hogan: ` Error: cannot find module 'hogan' ` with code straight from consolidate docs

I'm getting an Error: cannot find module 'hogan' when I send a request to the node.js server implemented in Coffeescript here:

https://gist.github.com/wmayner/306c89d7f8fbeed3f098

I've installed the dependencies hogan.js, consolidate, and express.

I've reproduced the example code from consolidate's documentation (reproduced below) almost exactly, so I'm having trouble seeing where this error is coming from. It looks like it should work.

From the consolidate docs:

var express = require('express')
  , cons = require('consolidate')
  , app = express();

// assign the swig engine to .html files
app.engine('html', cons.swig);

// set .html as the default extension 
app.set('view engine', 'html');
app.set('views', __dirname + '/views');

I've also tried declaring `hogan = require('hogan.js')' as a dependency.

Anyone have an idea why this is happening?

Note: The gist above differs from the consolidate docs in that I'm setting the view engine to hogan rather than html. This is because I'd rather use .hogan than .html for my template file extensions (I've tried .html and I get the same error).

Your gist sets hogan as view engine, but that should be html like in the Consolidate docs: 

// tell Express to use Consolidates 'hogan' renderer for .html templates
engines = require 'consolidate'
engine = 'hogan'
app.engine 'html', engines[engine]

// tell Express to use '.html' as extension to find views with .render()
app.set 'view engine', 'html'

EDIT: realizing that perhaps you want to use .hogan as extension for your template files, you could use this instead:

app.engine 'hogan', engines[engine]
app.set 'view engine', 'hogan'