script which shuffles .po file content from SSP-style codes to normal gettext() style msgid = EN, msgstr = XX language files, and back again

Commit 1edc1264 replaced Travis CI with GitHub Actions. These are
configured through the `.github` directory.

Commit 1edc1264 replaced Travis CI with GitHub Actions. Remove the
remaining references to Travis CI.

.coveralls.yml has been superceded by codecov.yml. Update the release
build script to delete the new file.

Our releases published to Packagist use version numbers with a
"v"-prefix, e.g. "v1.18.7".

The build-release script overwrites this with a version number without
the "v"-prefix, e.g. "1.18.7".

The result of this is that the composer.json in our release tar-files
does not match the composer.lock file in the repository nor the
composer.json that Packagist looks at.

Fix this by prepending a "v" to the version number when updating
composer.json.

* Added Kernel class to handle request

* Kernel handle request

Kernel is loaded in SimpleSAML\Module class
Removed Router and ControllerResolver classes

* Added route command (squash)

* Use symfony application and cache

* Updated to today's standards

* Fix for Symfony4 & Catch environment from ENV variable

* Standardize location of routes/services files

* Trying to make slashes work properly in all situations

* Convert XML to YML

* Fix some template-names and endpoints

* Rename Controller-classes

* Update dependencies

* Fix routing files

* TooManyArguments

* Fix TypeCoercion

* PSR-12

* Fix rebase mistake

* Rebase lock-file

* Fix Psalm

* Add strict_types declaration

Co-authored-by: Sergio Gómez <decano@gmail.com>

* 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