Adding test cases for submission_valid?
Adding test cases for submission_valid?

rmmaily/expertiza,redsock88/expertiza,arpitashekhar/expertiza,akshayjain114/expertiza,urmilparikh95/expertiza,joshio1/expertiza,redsock88/expertiza,KunmiaoYang/expertiza,michaelamoran/expertiza,mhhassan/expertiza,rmmaily/expertiza,KunmiaoYang/expertiza,joshio1/expertiza,sid5788/expertiza,ApertureScienceInnovators/expertiza,redsock88/expertiza,urmilparikh95/expertiza,expertiza/expertiza,redsock88/expertiza,joshio1/expertiza,akshayjain114/expertiza,KunmiaoYang/expertiza,sid5788/expertiza,kira0992/expertiza,arpitashekhar/expertiza,mhhassan/expertiza,michaelamoran/expertiza,rmmaily/expertiza,joshio1/expertiza,mhhassan/expertiza,expertiza/expertiza,urmilparikh95/expertiza,rmmaily/expertiza,kira0992/expertiza,akshayjain114/expertiza,akshayjain114/expertiza,michaelamoran/expertiza,KunmiaoYang/expertiza,kira0992/expertiza,mhhassan/expertiza,arpitashekhar/expertiza,expertiza/expertiza,ApertureScienceInnovators/expertiza,ApertureScienceInnovators/expertiza,urmilparikh95/expertiza,ApertureScienceInnovators/expertiza,michaelamoran/expertiza,sid5788/expertiza,sid5788/expertiza,expertiza/expertiza,arpitashekhar/expertiza,kira0992/expertiza