Updating the README of /test/
Updating the README of /test/

Added info for Usage of TestingExecutorUtil to create tables
yingjunwu/peloton,PauloAmora/peloton,cmu-db/peloton,haojin2/peloton,seojungmin/peloton,apavlo/peloton,cmu-db/peloton,malin1993ml/peloton,vittvolt/peloton,seojungmin/peloton,malin1993ml/peloton,haojin2/peloton,AllisonWang/peloton,AllisonWang/peloton,PauloAmora/peloton,seojungmin/peloton,vittvolt/peloton,AllisonWang/peloton,cmu-db/peloton,PauloAmora/peloton,apavlo/peloton,seojungmin/peloton,seojungmin/peloton,yingjunwu/peloton,cmu-db/peloton,haojin2/peloton,cmu-db/peloton,yingjunwu/peloton,malin1993ml/peloton,malin1993ml/peloton,yingjunwu/peloton,vittvolt/peloton,vittvolt/peloton,cmu-db/peloton,PauloAmora/peloton,AllisonWang/peloton,yingjunwu/peloton,haojin2/peloton,PauloAmora/peloton,AllisonWang/peloton,PauloAmora/peloton,haojin2/peloton,yingjunwu/peloton,malin1993ml/peloton,apavlo/peloton,vittvolt/peloton,apavlo/peloton,malin1993ml/peloton,seojungmin/peloton,vittvolt/peloton,apavlo/peloton,AllisonWang/peloton,haojin2/peloton,apavlo/peloton