Add BatchNorm operator

[owulveryck]

Add BatchNorm operator

[owulveryck]

Work in progress: cb12c18

By now:

• I simply discard the fourth and fifth input arguments
• I discard all but the first argument of the gorgonia operator.

the integration test fails wilth:

go test -run=Batchnorm integration_tests/batchnorm_epsilon_test.go integration_tests/batchnorm_example_test.go  integration_tests/settings_test.go
--- FAIL: TestBatchnormOp_epsilon (0.00s)
    batchnorm_epsilon_test.go:35: Cannot decode  Cannot apply Batchnorm operator: Failed to infer shape. Op: ⊙ false: Shape mismatch: (3) and (2, 3, 4, 5)
--- FAIL: TestBatchnormOp_example (0.00s)
    batchnorm_example_test.go:35: Cannot decode  Cannot apply Batchnorm operator: Failed to infer shape. Op: ⊙ false: Shape mismatch: (2) and (1, 2, 1, 3)
FAIL

[owulveryck]

I close this issue as I have partially implemented the batchnorm operator.
By partial I mean that only the forward pass without training has been coded without using the operator of gorgonia.