Javascript working in development locally but not production on Heroku

Question

I've spent hours trying to figure out why my Javascript isn't working correctly in production on Heroku, but working perfectly fine on my local development server. From my debugging it seems the compiled application.js isn't firing in production, although other javascript_inclued_tags are.

I use the Heroku Cedar-14 stack, and below are the relevant files:

Gemfile

source 'https://rubygems.org'
gem 'rails',                    '4.2.0'
gem 'bcrypt',                   '3.1.7'
gem 'faker',                    '1.4.2'
gem 'will_paginate',            '3.0.7'
gem 'bootstrap-will_paginate',  '0.0.10'
gem 'bootstrap-sass',           '3.2.0.0'
gem 'sass-rails',               '5.0.0.beta1'
gem 'fullcalendar-rails'
gem 'momentjs-rails',           '2.9.0'
gem 'uglifier',                 '2.5.3'
gem 'jquery-turbolinks',        '2.1.0'
gem 'bootswatch-rails',         '3.2.4'
gem "font-awesome-sass"
gem 'responders',               '~> 2.0'
gem 'mail_form',                '1.5.0'
gem 'simple_form',              '3.1.0.rc2'
gem 'stripe',                   '1.18.0'
gem 'carrierwave',              '0.10.0'
gem 'cloudinary'
gem 'attachinary',              '1.3.0'
gem 'mini_magick',              '3.8.0'
gem 'fog',                      '1.23.0'
gem 'coffee-rails',             '4.1.0'
gem 'jquery-rails',             '4.0.0.beta2'
gem 'turbolinks',               '2.3.0'
gem 'jbuilder',                 '2.2.3'
gem 'activeadmin',              github: 'activeadmin'
gem "parsley-rails"
gem 'icalendar'
gem 'geokit'
gem 'schoolfinder'
gem 'timezone'
gem 'impressionist'
gem 'devise'
gem 'rubillow'
gem 'business_time'
gem 'owlcarousel-rails'
gem 'bootstrap-datepicker-rails', '1.4.0'
gem 'bootstrap-slider-rails'
gem 'sdoc',                     '0.4.0', group: :doc
gem 'gmaps4rails'

group :development, :test do
 gem 'sqlite3',                '1.3.9'
 gem 'byebug',                 '3.4.0'
 gem 'web-console',            '2.0.0.beta3'
 gem 'spring',                 '1.1.3'
end

group :test do
 gem 'minitest-reporters',     '1.0.5'
 gem 'mini_backtrace',         '0.1.3'
 gem 'assert_json'
end

group :production do
 gem 'pg',                     '0.17.1'
 gem 'rails_12factor',         '0.0.2'
 gem 'unicorn',                '4.8.3'

end

Application.js

//= require jquery
//= require jquery.turbolinks
//= require jquery_ujs
//= require jquery.number
//= require functions
//= require bootbox.min
//= require jquery.ui.widget
//= require jquery.iframe-transport
//= require jquery.fileupload
//= require cloudinary/jquery.cloudinary
//= require attachinary
//= require houses
//= require turbolinks
//= require bootstrap
//= require moment
//= require moment-timezone-with-data-2010-2020
//= require bootstrap-datepicker/core
//= require bootstrap-datepicker/locales/bootstrap-datepicker.en-GB
//= require bootstrap-slider
//= require jquery.payment
//= require classie
//= require jquery.blueimp-gallery.min
//= require gsdk-bootstrapswitch
//= require gsdk-checkbox
//= require gsdk-radio
//= require jquery.validate
//= require jquery.bootstrap.wizard
//= require prettify
//= require index
//= require jquery.formatter
//= require elessar
//= require owl.carousel
//= require jquery-dateFormat.min
//= require perfect-scrollbar.jquery
//= require login
//= require agency
//= require wizard
//= require custom

environments/production.rb

Rails.application.configure do
  # Settings specified here will take precedence over those in config/application.rb.

  # Code is not reloaded between requests.
  config.cache_classes = true

  # Eager load code on boot. This eager loads most of Rails and
  # your application in memory, allowing both threaded web servers
  # and those relying on copy on write to perform better.
  # Rake tasks automatically ignore this option for performance.
  config.eager_load = true

  # Full error reports are disabled and caching is turned on.
  config.consider_all_requests_local       = false
  config.action_controller.perform_caching = true

  # Enable Rack::Cache to put a simple HTTP cache in front of your application
  # Add `rack-cache` to your Gemfile before enabling this.
  # For large-scale production use, consider using a caching reverse proxy like
  # NGINX, varnish or squid.
  # config.action_dispatch.rack_cache = true

  # Disable serving static files from the `/public` folder by default since
  # Apache or NGINX already handles this.
  config.serve_static_files = ENV['RAILS_SERVE_STATIC_FILES'].present?

  # Compress JavaScripts and CSS.
  config.assets.js_compressor = :uglifier
  # config.assets.css_compressor = :sass

  # Do not fallback to assets pipeline if a precompiled asset is missed.
  config.assets.compile = true

  # Asset digests allow you to set far-future HTTP expiration dates on all assets,
  # yet still be able to expire them through the digest params.
  config.assets.digest = true

  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb

  # Specifies the header that your server uses for sending files.
  # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX

  # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
  config.force_ssl = true

  # Use the lowest log level to ensure availability of diagnostic information
  # when problems arise.
  config.log_level = :debug

  # Prepend all log lines with the following tags.
  # config.log_tags = [ :subdomain, :uuid ]

  # Use a different logger for distributed setups.
  # config.logger = ActiveSupport::TaggedLogging.new(SyslogLogger.new)

  # Use a different cache store in production.
  # config.cache_store = :mem_cache_store

  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
  # config.action_controller.asset_host = 'http://assets.example.com'

  # Ignore bad email addresses and do not raise email delivery errors.
  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
  # config.action_mailer.raise_delivery_errors = false

  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
  # the I18n.default_locale when a translation cannot be found).
  config.i18n.fallbacks = true

  # Send deprecation notices to registered listeners.
  config.active_support.deprecation = :notify

  # Use default logging formatter so that PID and timestamp are not suppressed.
  config.log_formatter = ::Logger::Formatter.new

  # Do not dump schema after migrations.
  config.active_record.dump_schema_after_migration = false

  config.action_mailer.raise_delivery_errors = true
  config.action_mailer.delivery_method = :smtp
  host = 'virgentrealty.com'
  config.action_mailer.default_url_options = { host: host }
  ActionMailer::Base.smtp_settings = {
    :address        => 'smtp.sendgrid.net',
    :port           => '587',
    :authentication => :plain,
    :user_name      => ENV['SENDGRID_USERNAME'],
    :password       => ENV['SENDGRID_PASSWORD'],
    :domain         => 'heroku.com',
    :enable_starttls_auto => true
  }  
end