Fix indent to be two spaces

Author: cllns

lib/hanami/cli/ruby_file_generator.rb

@@ -23,7 +23,7 @@ def initialize(source_code)
         end
       end
 
-      INDENT = " "
+      INDENT = "  "
 
       def self.class(class_name, **args)
         new(class_name: class_name, **args).to_s