add attention method

(1) Densely Connected CNN with Multi-scale Feature Attention for Text Classification

Add attention on the last layer before classification.

(2) Attention-Mechanism-Containing Neural Networks for High-Resolution Remote Sensing Image Classification

(3) Learning Multi-Attention Convolutional Neural Network for Fine-Grained Image Recognition

(4) LEARN TO PAY ATTENTION

(5) Weighted Channel Dropout for Regularization of Deep Convolutional Neural Network