Update ci file and composer dependencies

[hotfix] The Mongo version in CI for 4.0 uses actually the 4

Merge branch 'master' of github.com:jenssegers/laravel-mongodb into add-use-new-library-for-coveralls

[refactor] Replaced Coveralls with Codecov

Pull from original repo

Add matrix for mongodb

HybridRelations::morphTo() needs to respect $ownerKey

Co-Authored-By: Stas <smolevich90@gmail.com>

[feature] StyleCI