Allow "^2.0|^3.0" psr/log versions

[lezhnev74]

WHY are these changes introduced?

Fixes #161

Allows to use this package with newer backend software.

WHAT is this pull request doing?

Changes allowed psr/log versions.

Type of change

• Patch: Bug (non-breaking change which fixes an issue)
• Minor: New feature (non-breaking change which adds functionality)
• Major: Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• I have added a changelog entry, prefixed by the type of change noted above
• I have added/updated tests for this change
• I have updated the documentation for public APIs from the library (if applicable)

[bostin]

any update ?

[fredden]

#211 has been merged in, which includes this change. This pull request can be safely closed.