Azure Pipelines: Fix codecov for PRs

[hugovk]

codecov: error: argument --token/-t: expected one argument

For example:

• #51
• https://dev.azure.com/hugovk/hugovk/_build/results?buildId=394

[hugovk]

This should now be fixed using the workaround:

• https://hynek.me/articles/simple-python-azure-pipelines/#coverage