features should not require users to manually include dependencies

[tamird]

See the features section of the README.

I think the usual pattern for this is:

• create a "runtime" crate with optional dependencies on log and trace which are reexported.
• add a dependency from test-log to "runtime". trace and log features enable "runtime"/log and "runtime"/trace, respectively.
• from test-log, refer to log and trace as "runtime"::log and "runtime"::trace, respectively.

This would produce a nicer user experience.

[d-e-s-o]

That sounds good to me. Feel free to open a pull request if you have time to work on it.