fix the failing tests

Fix the different failing tests
 - mock the events Dispatcher to avoid the error: ```ReflectionException: Class events does not exist```
 - fix the TMZ to avoid the error: ```mktime(): It is not safe to rely on the system's timezone settings.```
 - fix the Article::hasOne signature to avoid the warning: ```Declaration of Article::hasOne() should be compatible...```
 - specify the relation mock class in ArticleLang to avoid the error: ```LogicException: Relationship method must return an object of type Illuminate\Database\Eloquent\Relations\Relation```
 - remove trailing slash in expected route paths