use curl to download mnist dataset
use curl to download mnist dataset

Change-Id: I417e2399b5faa4a002525374327f8efd4d1ed3bc

cambridgehackers/connectal,chenm001/connectal,cambridgehackers/connectal,8l/connectal,csail-csg/connectal,hanw/connectal,cambridgehackers/connectal,8l/connectal,cambridgehackers/connectal,chenm001/connectal,chenm001/connectal,8l/connectal,8l/connectal,8l/connectal,hanw/connectal,cambridgehackers/connectal,hanw/connectal,hanw/connectal,chenm001/connectal,csail-csg/connectal,csail-csg/connectal,hanw/connectal,csail-csg/connectal,chenm001/connectal,csail-csg/connectal