added new function to retrieve by slug and post type
added new function to retrieve by slug and post type

lucasmichot/timber,aaemnnosttv/timber,mojaray2k/timber,asecondwill/timber,blocher/timber,timber/timber,xavierpriour/timber,xavivars/timber,timber/timber,gbarberi/timber,blocher/timber,josephbergdoll/timber,aprendiendoando/timber,gbarberi/timber,anugupta/timber,rpkoller/timber,Jmayhak/timber,PrisisForks/timber,Jmayhak/timber,josephbergdoll/timber,jarednova/timber,xavivars/timber,aaemnnosttv/timber,mojaray2k/timber,anugupta/timber,asecondwill/timber,PrisisForks/timber,anugupta/timber,ogrosko/timber,xavierpriour/timber,gchtr/timber,mgmartel/timber,gchtr/timber,joelgarciajr84/timber,blocher/timber,mgmartel/timber,rpkoller/timber,ogrosko/timber,jnweaver/timber,mgmartel/timber,pensesmart/timber,pensesmart/timber,gbarberi/timber,josephbergdoll/timber,aprendiendoando/timber,jarednova/timber,lucasmichot/timber,jnweaver/timber,aprendiendoando/timber,mojaray2k/timber,jnweaver/timber,joelgarciajr84/timber,joelgarciajr84/timber,xavierpriour/timber,aaemnnosttv/timber,Jmayhak/timber,rpkoller/timber,ogrosko/timber,pensesmart/timber,PrisisForks/timber,xavivars/timber,lucasmichot/timber,asecondwill/timber,jarednova/timber,gchtr/timber,asecondwill/timber