don't let the user wonder what command to use - just point it to him

* Adding support for HTTP Basic Auth when pulling from legacy repo

* added docs

* Adding unit test for http auth

* Adding mock to dev deps

* moved config reading logic to helper function, adapted test

* corrections

* rework pip_installer

* use source_reference as repo name when writing lock file and installing

Issue #61

* Allow empty license in init's license validation

* Add test for empty license in interactive init