New Dask + ITK blogpost

Now that [release [v5.3rc03](https://github.com/InsightSoftwareConsortium/ITK/tree/v5.3rc03) of ITK is available (which should include [this PR](https://github.com/InsightSoftwareConsortium/ITK/pull/2829)), it would be good to do a follow up blogpost [to this one](https://blog.dask.org/2019/08/09/image-itk) about using Dask + ITK together.

The purpose of this would be:
1. To tell other people that ITK images can now be serialized & used with Dask, in the hopes that they experiment with this on their own, and/or
2. in the event that we find there are still problems that need fixing, to document the current state of work.

The first step is re-running the code from the [earlier blogpost](https://blog.dask.org/2019/08/09/image-itk) with ITK v5.3rc03 or above and seeing whether that works or not. Then we write up whatever we find.

Here are the comments specifically discussing what should be included in a followup blogpost:
* https://github.com/InsightSoftwareConsortium/ITK/pull/2829#issuecomment-966068250
* https://github.com/InsightSoftwareConsortium/ITK/pull/2829#issuecomment-966805378
* https://github.com/InsightSoftwareConsortium/ITK/pull/2829#issuecomment-966806310

Links:
* Blogpost: https://blog.dask.org/2019/08/09/image-itk
* PR discussing blogpost: https://github.com/dask/dask-blog/issues/27
* PR enabling pickle serialization for ITK images: https://github.com/InsightSoftwareConsortium/ITK/pull/2829

Start by rerunning the code from the earlier Dask + ITK blogpost with ITK v5.3rc03 or above, then review the linked ITK PR comments for the follow-up content. Done means documenting whether the example works and writing the requested follow-up blogpost.

Written by the indexing model from the issue text.