Update SingleThreadAsyncNet
Update SingleThreadAsyncNet

Summary: Updated SingleThreadAsyncNet to use new interface

Reviewed By: ajtulloch

Differential Revision: D6526515

fbshipit-source-id: 6aa24678ba7350a5e448e9c2ab29ccd07a1fcb0b

Yangqing/caffe2,xzturn/caffe2,xzturn/caffe2,Yangqing/caffe2,xzturn/caffe2,Yangqing/caffe2,xzturn/caffe2,Yangqing/caffe2,Yangqing/caffe2,xzturn/caffe2,caffe2/caffe2