added pg as database in gem file
added updated Gemfile.lock, to deploy on heroku
added database file
added production database enviroment parameter
updated development db config to allow heroku deployment
read the build behavior session on heroku dev site.
the database.yml file is regenerated each time when the app is built. therefore, one need to specify the database parameters in the template file.
local will assume the development parameter. trying again with heroku
commented out the default in development
added the adapter setting in database.yml.pg