add KernelClient to IPython.kernel namespace

IPython/kernel/__init__.py

@@ -1,10 +1,11 b''
 """IPython kernels and associated utilities"""
 
 # just for friendlier zmq version check
 from . import zmq
 
 from .connect import *
 from .launcher import *
+from .client import KernelClient
 from .manager import KernelManager
 from .blocking import BlockingKernelClient
 from .multikernelmanager import MultiKernelManager