Update further to ipykernel comm refatoring

Author: echarles

docs/source/comms.rst

@@ -78,7 +78,7 @@ containing Javascript to connect to it.
         # Send data to the frontend on creation
         comm.send({'foo': 5})
 
-    get_ipython().kernel.comm_manager.register_target('my_comm_target', target_func)
+    get_ipython().comm.comm_manager.register_target('my_comm_target', target_func)
 
 This example uses the IPython kernel again; this example will be different in
 other kernels that support comms. Refer to the specific language kernel's

notebook/tests/services/serialize.js

@@ -33,7 +33,7 @@ casper.notebook_test(function () {
     this.then(function () {
         var index = this.append_cell([
             "import os",
-            "from IPython.kernel.comm import Comm",
+            "from IPython.comm.comm import Comm",
             "comm = Comm(target_name='echo')",
             "msgs = []",
             "def on_msg(msg):",