Discussion: Review logging / console output for --log-level support

[benc-uk]

Currently all output is done via pkg/console.go which supports the following message levels, the levels are mapped to colours

• Error - red text
• Warning - yellow text
• Info - blue text
• Success - green text
• Debug - magenta text

The only one of these which is controllable is debug, which will only be output if the global --debug flag is passed to rover

We could replace --debug with a --log-level flag and map that level to the existing 5 levels or do we want to step back and examine logging & output in more depth

Thoughts / ideas:

• Switch to a logger like https://github.com/sirupsen/logrus or https://github.com/uber-go/zap
  • This will probably give us log file and stdout support
  • Also a more structured set of levels
  • Note. Zap seems heavily focused on performance, which is not important