CI

CI (GitHub actions) has a new template system that will ease the go releases' upgrade.
On top of that, it now has a custom runner for ARM64. This leads to discovering and fixing a couple of issues in the tests on ARM64.

Fixes

• Support flat weights for the BatchNorm op (#465)
• fix the reset method of the tape machine (#467)
• fix clipping in Adam solver (#469)
• fix panic message in GlorotEtAlN64 (#470)
• fix concurrent example (#472)

API change

• functions to create primitive Value types (NewF64, NewF32, ...) (#481)
• Breaking change: the BatchNorm1d function has been removed; BatchNorm function supports 1d and 2d operations (#482)