Move some dependencies to the Gemfile

Gemfile

@@ -3,3 +3,17 @@
 source 'https://rubygems.org'
 
 gemspec
+
+group :development, :test do
+  gem 'activestorage', '~> 6.0'
+  gem 'capybara', '~> 3.33'
+  gem 'puma', '~> 4.3'
+  gem 'rspec_junit_formatter', '~> 0.4'
+  gem 'rspec-rails', '~> 4.0'
+  gem 'rubocop', '~> 1.0'
+  gem 'selenium-webdriver', '~> 3.142'
+  gem 'sprockets-rails', '~> 3.2'
+  gem 'sqlite3', '~> 1.4'
+
+  gem 'pry-rails'
+end