FIX: create a newline before group, github and source

[masakazutakewaka]

Summary

Add newlines before group, source(with block) and github(outside block)

fix #35285

master

gem 'fake'
source 'http://gems.github.com' do
  gem 'rspec-rails'
end
github 'user/repo' do
  gem 'foo'
end
group :development do
  gem 'fuga'
end
group :magic do
  github 'user/repo' do
    gem 'foo'
  end
  github 'user/repo2' do
    gem 'foo2'
  end
end

this branch

gem 'fake'

source 'http://gems.github.com' do
  gem 'rspec-rails'
end

github 'user/repo' do
    gem 'foo'
end

group :development do
  gem 'fuga'
end

group :magic do
  github 'user/repo' do
    gem 'foo'
  end
  github 'user/repo2' do
    gem 'foo2'
  end
end

reference

#35285 (comment)