* Rename from community.kubernetes to kubernetes.core
This goes through and renames community.kubernetes to kubernetes.core.
Most of this was generated from the downstream build script that was
used on the community repository, plus whatever hand edits I could find
that were needed.
The downstream build and test process has also been removed as this
repository is now the downstream repository.
* Fix CONTRIBUTING.md
* Issue #254: Fix 'unbound variable' error with empty array.
* Issue #254: Make downstream-release work completely.
* Make sed commands cross-platform.
* Issue #254: Add changelogs for 1.1.0.
* Issue #254: Two of the changes are major.
* Update CHANGELOG and galaxy tag version.
* Issue #254: Document kubernetes.core release process.
