Silence warning in mailer preview path check

Author: JonRowe

example_app_generator/spec/verify_mailer_preview_path_spec.rb

@@ -33,6 +33,8 @@ def capture_exec(*ops)
               .reject { |line| line =~ /DEPRECATION WARNING/ }
               .reject { |line| line =~ /warning: previous/ }
               .reject { |line| line =~ /warning: already/ }
+              .reject { |line| line =~ /but will no longer be part of the default gems / }
+              .reject { |line| line =~ /You can add .* to your Gemfile/ }
               .join
               .chomp
     CaptureExec.new(out, $?.exitstatus)