[FEATURE] Add a logger to Chelsea!

[DarthHater]

• What are you trying to do?

Right now Chelsea does not have a logger! It could use one!

• What feature or behavior is this required for?

Basically, if something breaks in Chelsea, we don't have a way to ask users for more information without some painful steps, adding a logger will help us avoid this.

• How could we solve this issue? (Not knowing is okay!)

Solving this technically, more or less find a good Ruby logger library (whatever is standard may work, more or less, but if you find something cool that makes sense, go for it)

The only hard requirements are:

• Write logs to ~/.ossindex/chelsea.combined.log
• Logging by default should be at ERROR level
• Introduce a command line flag ( -v -vv -vvv is more or less what we use in the other tools) that will bump the logging from ERROR -> INFO -> DEBUG -> TRACE
• Introduce some amount of logging (that we can continue to add to) that logs:
  • ERRORS as ERROR
  • INFO (stuff like I'm about to do this thing!)
  • DEBUG (stuff like I'm doing this thing and I sent this/recieved this)
  • TRACE (very fine grained, maybe I'm in a loop and I'm doing x with y type things)

As well, make the logger single use, as in rewrite it on each use (truncate existing file, start writing to it again). Other wise, you will need to think about log rotation, and potentially created large amounts of logs that need cleaned up. Single use I believe makes sense since these tools are largely single use tools, rather than services.

• Anything else?

This will be super helpful! Have fun!

cc @bhamail / @DarthHater / @brittanybelle / @gmohre