Prepare for 0.8.2 release.

Fix 0-area Polygon centroid calculation

Merge georust#199

199: Prepare for 0.8.0 release. r=frewsxcv a=frewsxcv



Co-authored-by: Corey Farwell <coreyf@rwell.org>

prepare for 0.7.4 release

prepare for 0.7.3 release

prepare for 0.7.2 release

Prepare for 0.7.1 release.

prepare for 0.7.0 release

Prepare for 0.6.3 release.

Prepare for 0.6.2 release.