Fix in error stub for Ruby 2.6 + Rails 5.0

Author: bknoles

spec/inertia/rspec_helper_spec.rb

@@ -10,6 +10,10 @@ def initialize
   def write(msg)
     @messages << msg
   end
+
+  # Rails 5.0 + Ruby 2.6 require puts to be a public method
+  def puts(thing)
+  end
 end
 
 RSpec.describe InertiaRails::RSpec, type: :request do