Update HISTORY.rst, fix date for release v0.6.0 (dask#212)

Add release notes for v0.6.0 (dask#202)

Fix spacing in HISTORY.rst

Add GPU support for local_threshold with method='mean' (dask#158)

Adds the fix suggested in cupy/cupy#3909

Add GPU support for local_threshold with method='mean' (dask#158)

Adds the fix suggested in cupy/cupy#3909

Update HISTORY.rst with release notes for 0.4.0 (dask#156)

Fix another typo in HISTORY.rst (dask#144)

Fix formatting of HISTORY.rst (dask#143)

* Fix formatting of HISTORY.rst

* Update HISTORY.rst

Fix formatting of HISTORY.rst (dask#143)

* Fix formatting of HISTORY.rst

* Update HISTORY.rst

Automate releases (dask#2)

* Copy automated release process from napari

* Move requirements to centralized location

* Release tools requirements

* Convenience files for pip installing requirements

* Fix flake8 failure in generate_release_notes.py

* Add release note backlog

* Add note acknowledging Kira