some style changes to application_helper_test to improve readability,
see [Ruby Style Guide](https://github.com/bbatsov/ruby-style-guide)
fix all Errors and Failures caused by comment_controller_test
* fix incorrect use of assert_template in place of assert_redirected_to
* fix mass assignment Errors
* some style changes to improve readability,
see [Ruby Style Guide](https://github.com/bbatsov/ruby-style-guide)
* miscellaneous other fixes
fix all Errors and Failures caused by conference_controller_test
* fix incorrect use of assert_template with unknown keys or
  instead of assert_redirected_to
* fix mass assignment Errors
* modernize query syntax
* some style changes to improve readability,
see [Ruby Style Guide](https://github.com/bbatsov/ruby-style-guide)
* miscellaneous other fixes