ResNet training tutorial is using brew instead of CNNModelHelper now
ResNet training tutorial is using brew instead of CNNModelHelper now

Summary:
Closes #650
Closes https://github.com/caffe2/caffe2/pull/651

Reviewed By: Yangqing

Differential Revision: D5124103

Pulled By: salexspb

fbshipit-source-id: 5325221757149de20bfd1b5552fe6df547dae5b4

sf-wind/caffe2,caffe2/caffe2,bwasti/caffe2,pietern/caffe2,bwasti/caffe2,bwasti/caffe2,pietern/caffe2,xzturn/caffe2,sf-wind/caffe2,Yangqing/caffe2,davinwang/caffe2,Yangqing/caffe2,sf-wind/caffe2,pietern/caffe2,Yangqing/caffe2,pietern/caffe2,xzturn/caffe2,Yangqing/caffe2,davinwang/caffe2,sf-wind/caffe2,pietern/caffe2,davinwang/caffe2,bwasti/caffe2,davinwang/caffe2,xzturn/caffe2,bwasti/caffe2,sf-wind/caffe2,xzturn/caffe2,xzturn/caffe2,davinwang/caffe2,Yangqing/caffe2