Add vendor/Dancer-Plugin-Auth-Extensible-Provider-SIP2 submodule
Add SIP2 to the Auth::Extensible config
Add vendor/ dir to path in bin/app.pl
Add Biblio-SIP2 as a submodule

This is a fork of https://github.com/dpavlin/Biblio-SIP2
Add SIP2 config to config.yml, for now
Update submodules