remove comma and check in init

Author: madhur-ob

metaflow/__init__.py

@@ -147,7 +147,8 @@ class and related decorators.
 from . import tuple_util
 
 # Runner API
-from .metaflow_runner import Runner
+if sys.version_info >= (3, 7):
+    from .metaflow_runner import Runner
 
 __version_addl__ = []
 _ext_debug("Loading top-level modules")

metaflow/metaflow_runner.py

@@ -73,11 +73,7 @@ async def stream_log(self, stream: str, position: Optional[int] = None):
 
 class Runner(object):
     def __init__(
-        self,
-        flow_file: str,
-        profile: Optional[str] = None,
-        env: Dict = {},
-        **kwargs,
+        self, flow_file: str, profile: Optional[str] = None, env: Dict = {}, **kwargs
     ):
         """
         Metaflow's Runner API that presents a programmatic interface