Logger configuration

[mj-will]

Currently, the logger in bilby adds handlers by default (see here). This goes against the recommend practice:

Note: It is strongly advised that you do not add any handlers other than NullHandler to your library’s loggers. This is because the configuration of handlers is the prerogative of the application developer who uses your library. The application developer knows their target audience and what handlers are most appropriate for their application: if you add handlers ‘under the hood’, you might well interfere with their ability to carry out unit tests and deliver logs which suit their requirements.

I think we should consider changing this, what do people think?

[ColmTalbot]

I'm in favour in principle, I think we should make it straightforward to maintain the current behaviour as I suspect people will expect it, but I think this can be done via a change in bilby_pipe, updates to the example scripts, and (as always) writing some documentation.

[mick-wright]

As a developer of a downstream pipeline, it would be handy for this to be the case. Currently, to get around it, I have my own logging functions hijack the bilby/bilby_pipe loggers.