Added tests for smarter _set_where
Added tests for smarter _set_where

rakesh-mohanta/codeigniter-base-model,marciocamello/codeigniter-base-model,manozdebnath/codeigniter-base-model,sergomet/codeigniter-base-model,nelson6e65/codeigniter-base-model,nguyenanhnhan/codeigniter-base-model,jamierumbelow/codeigniter-base-model,jahanzaibbahadur/codeigniter-base-model,chanakaDe/codeigniter-base-model