Move ploomber output to log file instead of printing to console

[TeaganKing]

We are implementing logging in #127 , mostly in order to provide options for various levels of printing to the console. However, the logging for ploomber output needs to be dealt with differently than the rest of our logging due to the structure of ploomber.

As noted in the aforementioned PR, this page provides some examples of basic pipelines that can be used to set up logging for ploomber; however, this calls dag in a slightly different manner and will require a bit more looking into, hence the additional issue ticket.