Add .gitlab-ci.yml and test Ruby app

src/ruby_gem/spec/ruby_gem_spec.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+RSpec.describe RubyGem do
+  it "has a version number" do
+    expect(RubyGem::VERSION).not_to be nil
+  end
+
+  it "does something useful" do
+    expect(false).to eq(true)
+  end
+end

src/ruby_gem/spec/spec_helper.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+require "ruby_gem"
+
+RSpec.configure do |config|
+  # Enable flags like --only-failures and --next-failure
+  config.example_status_persistence_file_path = ".rspec_status"
+
+  # Disable RSpec exposing methods globally on `Module` and `main`
+  config.disable_monkey_patching!
+
+  config.expect_with :rspec do |c|
+    c.syntax = :expect
+  end
+end