additional_information_callback can consume now pytest.Item

The additional_information_callback decorator can now consume optionally a keyword argument item: pytest.Item.

Fixing broken schema

• fixes #48

Logging stage consumes custom record formatter class

• Setting a custom record formatter class for logging is now possible

More information and customization of stages

• Adding more information to the test documents
• Making installation more stable
• Deprecating older Python versions
• Custom stage settings