[Feature Request] Print reporting to stdout

[MartinThoma]

I want to include liccheck into a CI pipeline. It would be nice if it created a formatted output. I propose to add a flag --report-to-stdout which would create this output:

Liccheck checked 63 packages:
* 62 OK
* 1 UNKNOWN

State Package name                License                
--------------------------------------------------------------------------------
OK    Flask 1.1.2                 BSD-3-Clause           
OK    cryptography 3.4.6          BSD or Apache License, Version 2.0
OK    paramiko 2.7.2              GNU Library or Lesser General Public Lice...