Log Message:
py-ipykernel: updated to 4.8.0

4.8.0
- Cleanly shutdown integrated event loops when shutting down the kernel.
- %gui qt now uses Qt 5 by default rather than Qt 4, following a similar
  change in terminal IPython.
- Fix event loop integration for :mod:asyncio when run with Tornado 5,
  which uses asyncio where available.