We remove the functionality to see all auth sources and to test them
publically. Testing the auth sources can be done inside the admin
module.

Added is a configuration option that allows the administrator to specfy
another place to redirect to for people who land on the front page.

updated twig to version 3 and added wrapper for translation via symfony/twig-bridge

Co-authored-by: Ulrik nielsen <un@ipwsystems.dk>

Fixes 336b7abe which changed the label from
'Login' to a single-use 'Log in' whilste the translations only have 'Login'.

These pages are now handled by the admin module. Add redirects
to the new locations.

* Remove deprecated classes

* Remove support for certificate fingerprints

* Remove many deprecated methods and pieces of code

* Remove SAML1.1/Shib1.3 support

* Remove many superfluous annotations

* Update unit test to work with new PHPunit

Closes #1268 
Closes #1020 
Closes #431 
Closes #167 
Closes #151 

* Migrate assertions to Webmozart

In the modern template also clean up HTML a bit.

Template would fail because key does not exist, when default() is
not immediately after it. So need to split this up.

* Use strict variables in Twig, except for our TemplateTest; throw exception on missing variables

* Fix issues due to Twig strict_variables=true

* Fix for #1229

* Fix metadata-template

The code generated: `$metadata['idp'] => array();` causing an error when I used this to copy the metadata and pasted it in the `metadata/saml20-idp-remote.php` file of another server.