Initial heroku integration
Heroku integration with foreman

Add foreman configuration for Heroku:
- To test production configuration execute NODE_ENV=production foreman
  start
- Database connection configuration now handles "use_env_variable" which
  should be defined as a environment variable such as "DATABASE_URL"
  with a proper database URI connection string, ie:
  postgres://user:password@db.example.com:5432/database
- Added package.json configuration to run migrations and db seed after
  `npm install`

Update frontend models to match sequelize definition.
Update views to work according to the changes above.
Handling isCompleted and parentId apropiately for PostgreSQL databases
Changed HTTP listening port for production
Add option to override port configuration with environment variable: PORT
Update README.md with heroku deploy steps
Update heroku deploy steps
Added repository field on package.json
Update install steps
Fixed tasks' parent update
Added heroku app.json manifest
Update app.json

Fix addon wrong name: heroku-postgresql:dev is heroku-postgresql
Update README.md

Minor fixes
Update app.json

Removed empty postscript block causing deploy failure.
Merge pull request #17 from abhshkdz/heroku-integration

Heroku integration