3.0.0 - 2018/01/12

* 2018-01-12 [TASK] Raise version number
* 2018-01-12 [TASK] Update documentation
* 2018-01-15 [TASK] Introduce Functional Tests
* 2018-01-15 [BUGFIX] Reset $this->getParameter for each link
* 2018-03-01 [TASK] Remove composer.lock
* 2018-03-01 [TASK] Fix GitLab CI cache key
* 2018-03-21 [BREAKING] Drop TYPO3 7.6 support
* 2018-03-29 [TASK] add "validRelation" so we can control output in Signal/Slot backend_beforeRenderSingleHreflangAttribute and frontend_beforeRenderSingleTag

There is still one open TODO: Test, what happens when there are nested mountpoints.