Updated tag 4.0.0

Merge pull request microsoft#892 from JordanMaples/dev/jomaples/gsl3.1.0

Update project version to GSL 3.1.0

Merge pull request microsoft#870 from beinhaerter/suppress_span_warning

suppress code analysis warning

Merge pull request microsoft#870 from beinhaerter/suppress_span_warning

suppress code analysis warning

Merge pull request microsoft#861 from JordanMaples/dev/jomaples/lwg3320

implement LWG3320

Merge pull request microsoft#826 from JordanMaples/dev/jomaples/ctad_…

…fix_v2

fix ctad warning in llvm

span constructor no address (microsoft#723)

* Changed &arr[0] to std::array<T, N>::data and std::address_of to protect against overloaded operator&.

* Removed the usage of `std::addressof` because it is a C++ 17 feature. Using decay for C arrays instead.

* Add unit tests for microsoft#662.

* Added c++17 test configurations for clang5.0 and clang6.0

* fixed CppCoreCheck pointer decay warning

Started versioning. Tested by SA team