Ipykernel

- Fix message-ordering bug that could result in out-of-order
executions, especially on Windows [356](https://github.com/ipython/ipykernel/pull/356)
- Fix classifiers to indicate dropped Python 2 support
[354](https://github.com/ipython/ipykernel/pull/354)
- Remove some dead code [355](https://github.com/ipython/ipykernel/pull/355)
- Support rich-media responses in `inspect_requests` (tooltips)
[361](https://github.com/ipython/ipykernel/pull/361)

- Drop support for Python 2. `ipykernel` 5.0 requires Python >= 3.4
- Add support for IPython's asynchronous code execution
[323](https://github.com/ipython/ipykernel/pull/323)
- Update release process in `CONTRIBUTING.md` [339](https://github.com/ipython/ipykernel/pull/339)

- Fix compatibility with IPython 7.0 [348](https://github.com/ipython/ipykernel/pull/348)
- Fix compatibility in cases where sys.stdout can be None
[344](https://github.com/ipython/ipykernel/pull/344)

- Python 3.3 is no longer supported [336](https://github.com/ipython/ipykernel/pull/336)
- Flush stdout/stderr in KernelApp before replacing
[314](https://github.com/ipython/ipykernel/pull/314)
- Allow preserving stdout and stderr in KernelApp
[315](https://github.com/ipython/ipykernel/pull/315)
- Override writable method on OutStream [316](https://github.com/ipython/ipykernel/pull/316)
- Add metadata to help display matplotlib figures legibly
[336](https://github.com/ipython/ipykernel/pull/336)