Migrate db to postgress

[XaoGao]

After #7 #9. We want to use postgress for our project

1. Add in gem to Gemfile pg last version https://rubygems.org/gems/pg
2. Run

bundle install

3. Change database.yml file to
   default: &default
   adapter: postgresql
   encoding: unicode
   pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
   port: <%= ENV.fetch("DATABASE_PORT") %>
   host: <%= ENV.fetch("DATABASE_HOST") %>
   user: <%= ENV.fetch("POSTGRES_USER") %>
   password: <%= ENV.fetch("POSTGRES_PASSWORD") %>

development:
<<: *default
database: rubywork_ru_development

test:
<<: *default
database: rubywork_ru_test

production:
<<: *default
database: rubywork_ru_production

3. Run

rails db:create && rails db:migrate

4. Launch project, open browser localhoat:3000 and check DB have users table

[zarina86]

I want to do this task

[XaoGao]

@zarina86 ok