Update requirements for six

[inuik]

Description of Problem, Request, or Question

The dependency requirement to six is restricting the latest version. As a result the following error is thrown by pip when installing to a different target directory.
conan-package-tools 0.34.2 requires six<1.15.0,>=1.10.0, but you'll have six 1.15.0 which is incompatible.

Looking at conan 1.29.0, the requirement is six<=1.15.0,>=1.10.0.

Environment Details

• Conan Package Tools Version: 0.34.2
• Operating System: Windows
• Operation System Version: Windows 10
• Conan version: conan 1.29.0
• Python version: python 3.7.4

Steps to reproduce (Include if Applicable)

1. pip install conan-package-tools
2. pip install --target=C:\temp packaging

Installing collected packages: six, pyparsing, packaging
ERROR: conan-package-tools 0.34.2 requires six<1.15.0,>=1.10.0, but you'll have six 1.15.0 which is incompatible.
Successfully installed packaging-20.4 pyparsing-2.4.7 six-1.15.0

[rasjani]

I know six has some extra stuff too not, just compatibility between 2 & 3 but everything below python 3.6 has been EOL'd so is there even rationale to six as dependency still ? ;)

[uilianries]

We can't use 1.16.0 because Conan only accepts <=1.15.0. If you want to run a newer version here, please, open a PR to https://github.com/conan-io/conan first.

[gost-serb]

Starting from 1.40.0 conan supports six version up to 1.16.0. Can this dependency be updated for conan-package-tools too?