title: Event loop is running error on starting jupyter notebook
body: <p>For some odd reason, after last night my jupyter kernel wouldn't start so I went ahead and removed it and pip3 installed it and now everytime I run <code>jupyter notebook</code> Im getting the following long stack trace in the termninal</p>
  
  <pre><code>[I 14:59:43.566 NotebookApp] Writing notebook server cookie secret to /run/user/1000/jupyter/notebook_cookie_secret
  [I 14:59:43.885 NotebookApp] Serving notebooks from local directory: /home/dmitri/machine_learning/airbusShipDetection
  [I 14:59:43.885 NotebookApp] The Jupyter Notebook is running at:
  [I 14:59:43.885 NotebookApp] http://localhost:8888/?token=b98d3bd1ec284b81559e0a865c14d6a0932e0725a99d811d
  [I 14:59:43.885 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
  [C 14:59:43.885 NotebookApp] 
  
      Copy/paste this URL into your browser when you connect for the first time,
      to login with a token:
          http://localhost:8888/?token=b98d3bd1ec284b81559e0a865c14d6a0932e0725a99d811d
  [I 14:59:44.624 NotebookApp] Accepting one-time-token-authenticated connection from 127.0.0.1
  [I 14:59:48.412 NotebookApp] Kernel started: 15342e49-8fc3-402c-9964-eb8f4e2324c5
  Traceback (most recent call last):
    File "/usr/lib/python3.5/runpy.py", line 184, in _run_module_as_main
      "__main__", mod_spec)
    File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
      exec(code, run_globals)
    File "/home/dmitri/.local/lib/python3.5/site-packages/ipykernel_launcher.py", line 16, in &lt;module&gt;
      app.launch_new_instance()
    File "/home/dmitri/.local/lib/python3.5/site-packages/traitlets/config/application.py", line 658, in launch_instance
      app.start()
    File "/home/dmitri/.local/lib/python3.5/site-packages/ipykernel/kernelapp.py", line 477, in start
      ioloop.IOLoop.instance().start()
    File "/usr/local/lib/python3.5/dist-packages/tornado/platform/asyncio.py", line 132, in start
      self.asyncio_loop.run_forever()
    File "/usr/lib/python3.5/asyncio/base_events.py", line 340, in run_forever
      raise RuntimeError('Event loop is running.')
  RuntimeError: Event loop is running.
  ERROR:tornado.general:Uncaught exception in ZMQStream callback
  Traceback (most recent call last):
    File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/zmqstream.py", line 432, in _run_callback
      callback(*args, **kwargs)
    File "/usr/local/lib/python3.5/dist-packages/tornado/stack_context.py", line 300, in null_wrapper
      return fn(*args, **kwargs)
    File "/home/dmitri/.local/lib/python3.5/site-packages/ipykernel/kernelbase.py", line 283, in dispatcher
      return self.dispatch_shell(stream, msg)
    File "/home/dmitri/.local/lib/python3.5/site-packages/ipykernel/kernelbase.py", line 233, in dispatch_shell
      self.pre_handler_hook()
    File "/home/dmitri/.local/lib/python3.5/site-packages/ipykernel/kernelbase.py", line 248, in pre_handler_hook
      self.saved_sigint_handler = signal(SIGINT, default_int_handler)
    File "/usr/lib/python3.5/signal.py", line 47, in signal
      handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
  ValueError: signal only works in main thread
  ERROR:tornado.general:Uncaught exception in zmqstream callback
  Traceback (most recent call last):
    File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/zmqstream.py", line 450, in _handle_events
      self._handle_recv()
    File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/zmqstream.py", line 480, in _handle_recv
      self._run_callback(callback, msg)
    File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/zmqstream.py", line 432, in _run_callback
      callback(*args, **kwargs)
    File "/usr/local/lib/python3.5/dist-packages/tornado/stack_context.py", line 300, in null_wrapper
      return fn(*args, **kwargs)
    File "/home/dmitri/.local/lib/python3.5/site-packages/ipykernel/kernelbase.py", line 283, in dispatcher
      return self.dispatch_shell(stream, msg)
    File "/home/dmitri/.local/lib/python3.5/site-packages/ipykernel/kernelbase.py", line 233, in dispatch_shell
      self.pre_handler_hook()
    File "/home/dmitri/.local/lib/python3.5/site-packages/ipykernel/kernelbase.py", line 248, in pre_handler_hook
      self.saved_sigint_handler = signal(SIGINT, default_int_handler)
    File "/usr/lib/python3.5/signal.py", line 47, in signal
      handler = _signal.signal(_enum_to_int(signalnum), _enum_to_int(handler))
  ValueError: signal only works in main thread
  [W 15:00:48.619 NotebookApp] Timeout waiting for kernel_info reply from 15342e49-8fc3-402c-9964-eb8f4e2324c5
  [I 15:01:49.148 NotebookApp] Saving file at /u-net-model-with-submission.ipynb
  ^C[I 15:02:46.820 NotebookApp] interrupted
  Serving notebooks from local directory: /home/dmitri/machine_learning/airbusShipDetection
  1 active kernel
  The Jupyter Notebook is running at:
  </code></pre>
  
  <p>The notebook itself says the kernel is loading, but it never finishes loading.</p>