add validation so collaborations cannot be between user and his or herself
add validation so collaborations cannot be between user and his or herself

heatseeknyc/heatseeknyc,ramillim/heatseeknyc,ramillim/heatseeknyc,heatseeknyc/heatseeknyc,heatseeknyc/heatseeknyc,ramillim/heatseeknyc