Add an option to configure the log format

[dagansandler]

Is your feature request related to a problem? Please describe. Currently, logs from pytest only show the log message and timestamp. This makes the log difficult to read and trace when something happens, as we may miss details of the log like the logger name, thread, code location, etc.

Describe the solution you'd like I would like to add the option to pass a rp_log_format option, similar to rp_log_level that will be used to format the log message.

[dagansandler]

I'm working on this feature myself, will send a PR soon, hopefully this can be merged.

[dagansandler]

PR submitted