* 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 

* Upgrade saml2-library to v4

* Stop considering Issuer-strings

* Stop considering NameID-arrays

* Bump to PHP 7.2

* Raise minimum PHP version to 7.0

* Remove tests pre-PHP 7.2

* Upgrade dev dependencies

* Ignore tests for deprecated class

* Add typehints; not touching public API

* Remove none-array replacements-param; old behaviour from pre-1.4 release

* Psalm fixes

* Add upgrade notes

* PSR-12

We have externalized the negotiate-module

* Externalize negotiate

* Install pecl-krb5

We need to include this in our travis-tests as long as we include the negotiate-module in the release

* Update Psalm

* Ignore DocblockTypeContradiction and RedundantConditionGivenDocblockType

* Fix Psalm-errors

* Raise minimum PHP-version to 5.6

* Update lock-file accordingly

* Fix phpunit

* Suppress Psalm-issue

HHVM is not compatible with Symfony4 and it is no longer worth the hassle

Closes #628

Ignore closure return types, as we need to support PHP < 7.

This is not really workable. Need to devise another way to run psalm
periodically without keeping it breaking the build.

This prevents a lot of -dev dependencies in composer.lock which are
not used otherwise and generate 'scary' warnings like "Package x is
abandoned".

Closes #718