Cli results and Output file

Hi @turboladen!

First scenario:
I want to be able getting the cli results as a hash. I need to manipulate them for an appropriate application. Then I created a new method on CLI that returns the critc.problems. Just that.

Second scenario:
Sometimes I want to be able printing the report into a yaml file. So I've created a new formatter for that. As a plus we can pass a output-file option on command-line or at config instantiation.

Tailor::CLI.new(
%w(--config-file=.tailor --output-file=my-file.yaml)
lib_to_analyze)

Tailor::CLI.new(
%w(--config-file=.tailor --output-file=my-file42.yaml)
other_lib_to_analyze)

This would be great for me, and, I guess, for us!
Can you check, please?

I didn't update the README yet. Let me know if all it's ok.
Thanks for advance!