#6029 Force Six version to 1.12.0 (#6031)
#6029 Force Six version to 1.12.0 (#6031)

Signed-off-by: Uilian Ries <d4bad57018205bdda203549c36d3feb0bfe416a7@gmail.com>
conan-io/conan,conan-io/conan,conan-io/conan