Merge branch 'hotfix/840'

Close #840
[2.1.5] Update version config
Merge branch 'releases/2.1.5'

2.1.5 readiness
Merge branch 'releases/2.1.5' into develop

2.1.5 readiness
Bump version

- 2.1.6dev (though likely next release will be 2.2.0)
Merge branch 'version/bump' into develop

Conflicts:
	docs/languages/en/conf.py