Add rspec

spec/imbecile_spec.rb

@@ -0,0 +1,5 @@
+RSpec.describe Imbecile do
+  it "has a version number" do
+    expect(Imbecile::VERSION).not_to be nil
+  end
+end

spec/spec_helper.rb

@@ -0,0 +1,14 @@
+require "bundler/setup"
+require "imbecile"
+
+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