message: Format validation script: use 'python3' instead of 'python' on Mac
diff: #!/bin/bash
  -python clang-format-validate.py --clang-format-executable ./clang-format_mac_10.0.0 \
  +python3 clang-format-validate.py --clang-format-executable ./clang-format_mac_10.0.0 \
  -r ../../Common ../../Graphics ../../Platforms ../../Primitives ../../Tests \
  --exclude ../../Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h \
  --exclude ../../Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h \
  