Strip errors generated from legacy variable names in .ctp files

*Details*
* History & threads indicate we shouldn't remove support in CakePHP 2.X
** https://github.com/cakephp/cakephp-codesniffer/pull/9
** https://github.com/cakephp/cakephp-codesniffer/issues/8
* This method felt like less of a hack than modifying the CakePHP Sniffs
** Unsure if the CakePHP Sniffs were even meant to be used for .ctp files