Ignore /tmp directory (used for tests)

Add Composer and Jetbrains template to .gitignore

Update deprecated SPDX license identifier

Add PHP 7.1 and 7.2 to .travis.yml

Add license file (GPL-3.0)

Update composer.json definition

Update README.

fix(composer): Update to base dependencies

fix(composer): Update to base dependencies

feat(php): Minor xdebug nesting level correction

feat(composer): Update baseline composer version

feat(gitlab): Improvements to gitlab-ci.yml

feat(gitlab): Improvements to gitlab-ci.yml

feat(namespace): Change organization namespace

feat(ci): Adjust namespace for repository