pin deps to python3.6 version

[hjmodi]

We are using python3.6 in testing setup and some deps are not available beyond certain version for python3.6

This might cause issue with python3.6 where latest versions are not available

Maintainers will complete the following section

• [x] Commit messages are descriptive enough
• [n/a] Code coverage from testing does not decrease and new code is covered
• [n/a] JSON/YAML configuration changes are updated in the relevant schema
• [n/a] Changes to metadata also update the documentation for the metadata
• [n/a] Pull request has a link to an osbs-docs PR for user documentation updates