Improve logging in the script

[andywaltlova]

Related to oamg/rhc-worker-script#100, when rhc-worker-script will be able to return progress reporting it would be great if we would have different levels of logging (based on the logging set for worker), that way we could either see the regular log that is outputed to stdout, or we could have debug/error logs.

[r0x0d]

Wonderful issue! we can try using the logging library for that.

Thinking more about that right now, maybe we could save the logs to a file too? That would help debug the system later. We can do the same set up we have for sosreport where we save the file to a specific folder too.