Ignore rubyforge_project warnings from captured output

Author: JonRowe

example_app_generator/spec/verify_mailer_preview_path_spec.rb

@@ -25,6 +25,7 @@ def capture_exec(*ops)
     # Necessary to ignore warnings from Rails code base
     out =  io.readlines.
               reject { |line| line =~ /warning: circular argument reference/ }.
+              reject { |line| line =~ /NOTE: Gem::Specification#rubyforge_project=/ }.
               join.
               chomp
     CaptureExec.new(out, $?.exitstatus)