____________________________________RVM gemset installation__________________________________
$ rvm gemset create project_name
$ rvm use 2.4.1@project_name                (2.4.1 - ruby version)
$ gem install rails
$ rails new project_name -d postgresql
$ cd project_name
$ git init
$ rvm --ruby-version use 2.4.1@project_name (2.4.1 - ruby version)
(create 2 files - ruby-gemset, ruby-version)

____________________________________Database installation____________________________________
$ cp config/database.yml config/database.yml.sample
(copying the database.yml file)
on database.yml delete group :production
add config/database.yml file to .gitignore

$ rake db:create:all (create database on postgre)

____________________________________Rspec installation_______________________________________
on Gemfile:
  group :test, :development do
    gem 'rspec-rails'
    gem 'factory_girl_rails'
  end
$ bundle install
$ rails generate rspec:install (rspec installation)

_____________________________________Delete mini-test________________________________________
$ rm -rf test
on .rspec file add:
  --format doc (for read documentation)

$ git add && git commit -m "Initial commit"