`objects.artifact` `delete` function docstring return type is incorrect

[kkaja123]

The docstring says that the ArtifactoryArtifact delete() method returns a bool, but it doesn't actually return a bool. self._delete returns an HTTP Response, so maybe that should be used to determine whether or not to return True or False. Otherwise, if delete shouldn't return anything, then remove the line from the docstring.

https://github.com/anancarv/python-artifactory/blob/1f05a4c654b3f631ba0bbe2a3c4b555bdb781046/pyartifactory/objects/artifact.py#L363-L367