[RELEASE] Release of crawler 6.6.0

[TASK] Add extension-release to composer scripts
[TASK] Setting up Travis CI with Deployment to TER on tags (400)
[BUGFIX] Change check for CLI request or backend request in CrawlerCommandController
[BUGFIX] Resolves the bin-dir from composer.json (357)
[TASK] Add tests for expandParameters (391)
[TASK] Deprecated functions not longer needed (390)
[TASK] Update documentation rendering to match new setup from docs-team (389)
[TASK] Deprecated functions (387)
[BUGFIX] Composer: Move system dependency (386)
[TASK] Add tests for CrawlerController (385)
[TASK] Update PHP Requirements (382)
[FEATURE] Use Extbase Domain/Model  Repository 323 (328)