v1.1

• Migrated code to PyTorch 1.0.0, removed Variable, added torch.no_grad for more speed and less memory at evaluation
• Added rigid grid regional pooling that can be combined with any global pooling method (R-MAC, R-SPoC, R-GeM)
• Added PowerLaw normalization layer
• Added multi-scale testing with any given set of scales, in example test script
• Fix related to precision errors of covariance matrix estimation during whitening learning
• Fixed minor bugs