* Atari Visualization Bugfix

OpenCV2 does not always display the visualization properly. 

For imshow to properly update, cv2.waitKey should be called. Without this line, the cv2 window does not refresh on my system with OpenCV version 2.4.9.1 on Debian with Python 2.7.9. More info can be found on [StackOverflow](https://stackoverflow.com/questions/44854699/why-does-the-cv2-imshow-does-not-render-without-cv2-waitkey).

* Remove unused import

* Fix se_resnet_bottleneck to support NHWC data format

* Fixed my fix: removed original line

* Remove trailing whitespace

* load model function in shufflenet

* cifar10-resnet-mixup implementation

* add two file

* code beatify

* 1,bn typo;2,cifar18 preact18 mixup code

* double epoch number

* two file into one file

* make travis happy

* preactblock error

* travis please happy

* result update

* clean-up duplicate sections

* Update schedule and readme

* add VGG19 demo

* add pretrained model url (upload will be later)

* fix vgg16 and fix linting in vgg19