Remove stale features/steps/project/builds.rb

Running git log --full-history -- features/steps/project/builds.rb, you can
see that this was renamed to features/steps/project/builds/artifacts.rb in
2016 via bf7aac74. You can't see the actual changes in GitLab, but
they show up if you run git diff da866795..30e4d3ce.

features/steps/project/builds.rb

-class Spinach::Features::ProjectBuilds < Spinach::FeatureSteps
-  include SharedAuthentication
-  include SharedProject
-  include SharedBuilds
-  include RepoHelpers
-
-  step 'I see summary for build' do
-    expect(page).to have_content "Build ##{@build.id}"
-  end
-
-  step 'I see build trace' do
-    expect(page).to have_css '#build-trace'
-  end
-
-  step 'I click artifacts download button' do
-    page.within('.artifacts') { click_link 'Download' }
-  end
-
-  step 'download of build artifacts archive starts' do
-    expect(page.response_headers['Content-Type']).to eq 'application/zip'
-    expect(page.response_headers['Content-Transfer-Encoding']).to eq 'binary'
-  end
-
-  step 'I click artifacts browse button' do
-    page.within('.artifacts') { click_link 'Browse' }
-  end
-
-  step 'I should see content of artifacts archive' do
-    page.within('.tree-table') do
-      expect(page).to have_no_content '..'
-      expect(page).to have_content 'other_artifacts_0.1.2'
-      expect(page).to have_content 'ci_artifacts.txt'
-      expect(page).to have_content 'rails_sample.jpg'
-    end
-  end
-
-  step 'I click link to subdirectory within build artifacts' do
-    page.within('.tree-table') { click_link 'other_artifacts_0.1.2' }
-  end
-
-  step 'I should see content of subdirectory within artifacts archive' do
-    page.within('.tree-table') do
-      expect(page).to have_content '..'
-      expect(page).to have_content 'another-subdirectory'
-      expect(page).to have_content 'doc_sample.txt'
-    end
-  end
-
-  step 'recent build artifacts contain directory with UTF-8 characters' do
-    # metadata fixture contains relevant directory
-  end
-
-  step 'I navigate to directory with UTF-8 characters in name' do
-    page.within('.tree-table') { click_link 'tests_encoding' }
-    page.within('.tree-table') { click_link 'utf8 test dir ✓' }
-  end
-
-  step 'I should see content of directory with UTF-8 characters in name' do
-    page.within('.tree-table') do
-      expect(page).to have_content '..'
-      expect(page).to have_content 'regular_file_2'
-    end
-  end
-
-  step 'recent build artifacts contain directory with invalid UTF-8 characters' do
-    # metadata fixture contains relevant directory
-  end
-
-  step 'I navigate to parent directory of directory with invalid name' do
-    page.within('.tree-table') { click_link 'tests_encoding' }
-  end
-
-  step 'I should not see directory with invalid name on the list' do
-    page.within('.tree-table') do
-      expect(page).to have_no_content('non-utf8-dir')
-    end
-  end
-
-  step 'I click download button for a file within build artifacts' do
-    page.within('.tree-table') { first('.artifact-download').click }
-  end
-
-  step 'download of a file extracted from build artifacts should start' do
-    # this will be accelerated by Workhorse
-    response_json = JSON.parse(page.body, symbolize_names: true)
-    expect(response_json[:archive]).to end_with('build_artifacts.zip')
-    expect(response_json[:entry]).to eq Base64.encode64('ci_artifacts.txt')
-  end
-end