v0.6.4-rc6

abfcc13 [Doc] Add beta note near relevant features in docs (#950)
2c63692 [Doc] Update installation guide with Docker Desktop instructions (#954)
bb70cad [Runtimes] Support loading nuclio functions from external code entry (#905)
6a61959 [Jupyter image] Use hackathon mlrun/demos branch, add graphviz & python-dotenv, remove examples (#957)
8326c36 [Datastore] Align DataFrameSource key_field column name to other sources (#959)
673ff5a [Requirements] Add pytest_tornasync to system tests as well (#958)
d298905 [Requirements] Bump nuclio-jupyter minimum to 0.8.14 (#947)