MobileNet operators

Context

close #5 (moved)

Complete the missing cuda operators' backends to run a MobileNetV2 inference:

• BatchNorm
• Reshape
• Add
• GlobalAveragePooling
• Pad
• ConvDepthWise

Modified files

• BatchNormImpl.hpp, BatchNormImpl.cpp and Test_BatchNormImpl.cpp, add BatchNorm cuda Impl;
• ReshapeImpl.hpp, ReshapeImpl.cpp and Test_ReshapeImpl.cpp, add Reshape cuda Impl;
• AddImpl.hpp, AddImpl.cpp and Test_AddImpl.cpp, add Add cuda Impl;
• GlobalAveragePoolingImpl.hpp, GlobalAveragePoolingImpl.cpp and Test_GlobalAveragePoolingImpl.cpp, add GlobalAveragePooling cuda Impl;
• PadImpl.hpp, PadImpl.cpp and Test_PadImpl.cpp, add Pad cuda Impl;
• ConvImpl.hpp, ConvImpl.cpp and Test_ConvDepthWiseImpl.cpp, add ConvDepthWise cuda Impl;

TODO

• DONE : Add "BatchNorm" Impl
• DONE : Add "Reshape" Impl
• DONE : Add "Add" Impl
• DONE : Add "GlobalAveragePooling" Impl
• DONE : Add "Pad" Impl
• DONE : Add "ConvDepthWise" Impl