Simplify `bin/feature-flag` script

Do not ask for type if it is only one.

bin/feature-flag

@@ -118,6 +118,9 @@ class FeatureFlagOptionParser
     end
 
     def read_type
+      # if there's only one type, do not ask, return
+      return TYPES.first.first if TYPES.one?
+
       $stdout.puts ">> Please specify the type of your feature flag:"
       $stdout.puts
       TYPES.each do |type, data|

spec/bin/feature_flag_spec.rb

@@ -115,6 +115,26 @@ RSpec.describe 'bin/feature-flag' do
     describe '.read_type' do
       let(:type) { 'development' }
 
+      context 'when there is only a single type defined' do
+        before do
+          stub_const('FeatureFlagOptionParser::TYPES',
+            development: { description: 'short' }
+          )
+        end
+
+        it 'returns that type' do
+          expect(described_class.read_type).to eq(:development)
+        end
+      end
+
+      context 'when there are many types defined' do
+        before do
+          stub_const('FeatureFlagOptionParser::TYPES',
+            development: { description: 'short' },
+            licensed: { description: 'licensed' }
+          )
+        end
+
         it 'reads type from $stdin' do
           expect($stdin).to receive(:gets).and_return(type)
           expect do
@@ -122,7 +142,7 @@ RSpec.describe 'bin/feature-flag' do
           end.to output(/specify the type/).to_stdout
         end
 
-      context 'invalid type given' do
+        context 'when invalid type is given' do
           let(:type) { 'invalid' }
 
           it 'shows error message and retries' do
@@ -136,6 +156,7 @@ RSpec.describe 'bin/feature-flag' do
           end
         end
       end
+    end
 
     describe '.read_group' do
       let(:group) { 'group::memory' }