Buffer Logger output & fix Chef run output formatting

For more detail you can check out the commit message for the included commits.

Turns out there were competing issues:

* Adding the explicit `--log_level info` option on `chef-solo` and `chef-client` were conflating both outputs together
* The SSH connection is requesting a TTY (for older/stock sudoers policies) which caused the Chef runs to believe they were running in interactive mode
* The interactive mode also enabled coloring which isn't necessary since Kitchen is coloring the output itself

When I attempted to use `--force-logger --log_level info` (in interactive) I was seeing double output of each line. When I force the Chef run to operate non-interactively (by piping through cat: `chef-solo -force-logger --log_level info ... | cat`) this resolved the double output.

It seems to me that fixing the output formatting will go so far to make things better here, but is it possible that a user will need to make use of the classic logger format and thus need an option to switch this out? I'm not sold either way, but no that any formatting cleanup will be an improvement and help bring clarity back to the Chef runs here.

@sethvargo, @someara, danielsdeleo: I'd love a second sober look at this to make sure I properly understood the output formatter/logger relationship.