Release v0.2.0

[markmandel]

• Review closed issues have appropriate tags.
• Review closed issues have been applied to the current milestone.
• Ensure the next version milestone is created.
• Any issues in the current milestone that are not closed, move to next milestone.
• Run make gen-changelog to generate the CHANGELOG.md
• Ensure the helm tag value is correct (should be the v0.2.0 if a full release, v0.2.0.rc if release candidate)
• Run make gen-install
• If RC release, update all ⚠️⚠️⚠️ warnings to: "This is currently a release candidate feature"
• If full release, remove all instances of "⚠️⚠️⚠️ This is currently a development feature and has not been released ⚠️⚠️⚠️"
• If full release, update install docs with the new release version
• Create PR with these changes, and merge them with approval
• Confirm local git remote upstream points at git@github.com:GoogleCloudPlatform/agones.git
• Run git checkout master && git reset --hard upstream/master to ensure your code is in line with upstream (unless this is a hotfix, then do the same, but for the the release branch)
• Run make do-release. (if release candidate make do-release RELEASE_VERSION=v0.2.0.rc) to create and push the docker images.
• Do a helm install and a smoke test to confirm everything is working.
• Create a release with the release template
  • Make a tag with the release version.
  • Attach all assets found in the release folder to the release.
• Send an email to the mailing list with the release details (copy-paste the github release)
• If full release, then increment the base_version in build/Makefile
• Ensure the the helm tag value is the same as the above base_version
• Create PR with these changes, and merge them with approval
• Close this issue.
• If full release, close the current milestone. Congratulations! - the release is now complete! 🎉 👏 😄 👍