Implement suggested changes

Author: nevesenin

lib/thor/parser/option.rb

@@ -105,7 +105,12 @@ def aliases_for_usage
     end
 
     def show_default?
-      super || [TrueClass, FalseClass].any? { |c| default.is_a?(c) }
+      case default
+      when TrueClass, FalseClass
+        true
+      else
+        super
+      end
     end
 
     VALID_TYPES.each do |type|

spec/parser/option_spec.rb

@@ -272,14 +272,14 @@ def option(name, options = {})
 
   describe "#print_default" do
     it "prints boolean with true default value" do
-      expect(option(:foo,    {
+      expect(option(:foo, {
         required: false,
         type: :boolean,
         default: true
       }).print_default).to eq(true)
     end
     it "prints boolean with false default value" do
-      expect(option(:foo,    {
+      expect(option(:foo, {
         required: false,
         type: :boolean,
         default: false