v2.2 release notes

[alimanfoo]

TODO:

• numcodecs change Use numcodecs #139
• visitor pattern Add visitor pattern methods #122
• astype AsType Filter #96, Fix representation of AsType's dtypes #120
• bug fixes, maintenance raise AttributeError in __getattr__ if lookup fails #95, Support LZMA on Python 2 via backports.lzma #123, Upgrade CI and dev environment #114, Use Coveralls #118, Data fixture #146, ...

[jakirkham]

Any thoughts on the items mentioned in issue ( https://github.com/alimanfoo/zarr/issues/144 )?

[alimanfoo]

I'm hoping to resolve some more of the items in #144 before making the 2.2 release. This issue is to remind me to write release notes for the changes already merged.

[jakirkham]

Ok, just noticed activity picked up here and wasn't sure what sort of timeline you had in mind for releasing. 😉 Might try and give the tree work another look (am feeling inspired). 😄

[alimanfoo]

Re timeline, I'm thinking maybe 4 weeks, to give some to work through a few more issues.