$ brew doctor
$ brew update
$ brew install postgresql

# if we want to run pg locally, we need to run the following instructions.

# To have launchd start postgresql at login:
ln -sfv /usr/local/opt/postgresql/*plist ~/Library/LaunchAgents

# Then to load and run postgresql immediately:
launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist

$ heroku login
$ heroku create

gem 'sqlite3'

group :development, :test do
  gem 'sqlite3'
end

group :production do
  gem 'pg'
  gem 'rails_12factor'
end

$ bundle install --without production

$ git add .
$ git commit -m "Changed Gemfile for heroku"

$ git push heroku master
$ heroku run rake db:migrate