Bump minimum versions for 0.16 release (#4175)

* Bump minimum versions for 0.16 release

* Undo scipy bump

* fix bumps

Author: dcherian

ci/requirements/py36-min-all-deps.yml

@@ -15,8 +15,8 @@ dependencies:
   - cfgrib=0.9
   - cftime=1.0
   - coveralls
-  - dask=2.5
-  - distributed=2.5
+  - dask=2.9
+  - distributed=2.9
   - flake8
   - h5netcdf=0.7
   - h5py=2.9  # Policy allows for 2.10, but it's a conflict-fest
@@ -26,11 +26,10 @@ dependencies:
   - isort
   - lxml=4.4  # Optional dep of pydap
   - matplotlib=3.1
-  - msgpack-python=0.6  # remove once distributed is bumped. distributed GH3491
   - mypy=0.761  # Must match .pre-commit-config.yaml
   - nc-time-axis=1.2
   - netcdf4=1.4
-  - numba=0.44
+  - numba=0.46
   - numpy=1.15
   - pandas=0.25
   # - pint  # See py36-min-nep18.yml

ci/requirements/py36-min-nep18.yml

@@ -6,9 +6,8 @@ dependencies:
   # require drastically newer packages than everything else
   - python=3.6
   - coveralls
-  - dask=2.5
-  - distributed=2.5
-  - msgpack-python=0.6  # remove once distributed is bumped. distributed GH3491
+  - dask=2.9
+  - distributed=2.9
   - numpy=1.17
   - pandas=0.25
   - pint=0.13

doc/whats-new.rst

@@ -22,6 +22,9 @@ v0.16.0 (unreleased)
 Breaking changes
 ~~~~~~~~~~~~~~~~
 
+- Minimum supported versions for the following packages have changed: ``dask >=2.9``,
+  ``distributed>=2.9``.
+  By `Deepak Cherian <https://github.com/dcherian>`_
 - ``groupby`` operations will restore coord dimension order. Pass ``restore_coord_dims=False``
   to revert to previous behavior.
 - :meth:`DataArray.transpose` will now transpose coordinates by default.