Fixes issue with Metadata describe method not sending results to the callback function.
Fixes issue with Metadata describe method not sending results to the callback function.

jdcrensh/jsforce,jesperkristensen/jsforce,jsforce/jsforce,jdcrensh/jsforce,saleswise/jsforce,joeferraro/jsforce,lkatney/jsforce,nutthawan/jsforce,jsforce/jsforce,bhaskarmelkani/jsforce,rdietrick/jsforce,jsforce/jsforce,parthiban019/jsforce,joeferraro/jsforce,pcon/jsforce,jesperkristensen/jsforce,lkatney/jsforce,nutthawan/jsforce,saleswise/jsforce,saleswise/jsforce,kimchouard/jsforce,pcon/jsforce,pcon/jsforce,parthiban019/jsforce,bhaskarmelkani/jsforce