add a note about setAsyncSpecTimeout in the readme
add a note about setAsyncSpecTimeout in the readme

segiddins/specta,ShawnLeee/specta,github/specta,alvinvarghese/specta,jmoody/specta,PatrykKaczmarek/specta,Vungle/specta,iguchunhui/specta,mickeyreiss/specta,lmtim/specta,hanangellove/specta,adamkaplan/specta,rad3ks/specta,Lightricks/specta,specta/specta,flovilmart/specta,ernestopino/specta,Taptera/specta,dbarden/specta,wessmith/specta,ashfurrow/specta,iosdev-republicofapps/specta,ExtremeMan/specta