BeakerX 0.16.0: Invoking ipython throws AttributeError: 'TerminalInteractiveShell' object has no attribute 'kernel' at beakerx_magics/kernel_magic.py", line 110 while trying to load_ipython_extension

```
$ docker run --rm -it vishnumohan/beakerx-dcos bash
beakerx@ac6698017c48:~$ ipython
Python 3.6.5 | packaged by conda-forge | (default, Apr 6 2018, 13:39:56)
Type 'copyright', 'credits' or 'license' for more information
IPython 6.3.1 -- An enhanced Interactive Python. Type '?' for help.
[TerminalIPythonApp] WARNING | Error in loading extension: beakerx_magics.kernel_magic
Check your config files in /home/beakerx/.ipython/profile_default
Traceback (most recent call last):
File "/opt/conda/lib/python3.6/site-packages/IPython/core/shellapp.py", line 244, in init_extensions
self.shell.extension_manager.load_extension(ext)
File "/opt/conda/lib/python3.6/site-packages/IPython/core/extensions.py", line 92, in load_extension
if self._call_load_ipython_extension(mod):
File "/opt/conda/lib/python3.6/site-packages/IPython/core/extensions.py", line 139, in _call_load_ipython_extension
mod.load_ipython_extension(self.shell)
File "/opt/conda/lib/python3.6/site-packages/beakerx_magics/kernel_magic.py", line 110, in load_ipython_extension
ipython.kernel.shell_handlers['comm_msg'] = comm_msg
AttributeError: 'TerminalInteractiveShell' object has no attribute 'kernel'
```