Stdout insights should not include HTML

[Horgix]

Currently, the stdout helpful insights from the Test step of recipes such as classification include HTML tags:

Test | Ep. 0 It 1 | {'acc': '0.0892', 'loss': '2.6739', 'cm': '<table><tr><th>Pred\\', 'report': '<h1>Best predictions', 'table': '\n        <style>\n   '}

I believe that these should not be part of the message since no terminal will render it and it only makes things harder to read!

[Vermeille]

My thinking was that some NLP people might actually want to write some textual output to the terminal.
However, as of today, StdoutLogger will print everything the state contains, including strings and VisdomLogger will render strings as HTML. I have no idea how to pull this off cleanly.