* dev:
Update composer lock file
Fix license reference in composer.json according to spdx.org
Add description and keywords to composer.json
Fix issues reported by scrutinizer; cherry-pick v1.1.2
Add more test cases for ImmutableValueImplSpec
Revert "Enable code coverage for Scrutinizer"
Revert "Update Scritinizer config to prevent from running PHP 7.3"
Update Scritinizer config to prevent from running PHP 7.3
Revert "Revert "Remove PHP 7.3 support for lack of coverage drivers""
Revert "Remove PHP 7.3 support for lack of coverage drivers"
Require xdebug to make code coverage work for Scrutinizer
Enable code coverage for Scrutinizer
Remove PHP 7.3 support for lack of coverage drivers
Ignore code coverage results within doc/
Change criteria for Travis CI runner
Require code coverage extension for PhpSpec and configure it