add planet.sync namespace

Author: asonnenschein

planet/__init__.py

@@ -19,8 +19,6 @@
 from .clients import DataClient, OrdersClient, SubscriptionsClient  # NOQA
 from .io import collect
 
-from .client import Planet
-
 __all__ = [
     'Auth',
     'collect',
@@ -29,7 +27,6 @@
     'OrdersClient',
     'order_request',
     'reporting',
-    'Planet',
     'Session',
     'SubscriptionsClient',
     'subscription_request'