Add user._id to interest document.
Add user._id to interest document.

plauer/Brainstorm,EJJ-Brainstorm/Brainstorm,JulieMarie/Brainstorm,JulieMarie/Brainstorm,ekeric13/Brainstorm,EJJ-Brainstorm/Brainstorm,ekeric13/Brainstorm,HRR2-Brainstorm/Brainstorm,drabinowitz/Brainstorm