fix import (#222)

Fix of importing Dataset, Datastore, Workspace

Author: jotaylo

diabetes_regression/training/train_aml.py

@@ -23,7 +23,8 @@
 ARISING IN ANY WAY OUT OF THE USE OF THE SOFTWARE CODE, EVEN IF ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGE.
 """
-from azureml.core.run import Dataset, Datastore, Run, Workspace
+from azureml.core.run import Run
+from azureml.core import Dataset, Datastore, Workspace
 import os
 import argparse
 import joblib