chore: release 0.2.7 (#74)

- Release v0.2.7
- Add `RELEASING.md` to clarify the release process

RELEASING.md

@@ -0,0 +1,36 @@
+## Release guide for team members
+
+To build and publish a new version of `secure-setup-terraform`, including publishing binaries for
+all supported OSes and architectures, complete the following steps:
+
+- Find the previously released version. You can do this by looking at the git
+  tags or by looking at the frontpage of this repo on the right side under the
+  "Releases" section.
+
+- Figure out the version number to use. We use "semantic versioning"
+  (https://semver.org), which means our version numbers look like
+  `MAJOR.MINOR.PATCH`. Quoting semver.org:
+
+        increment the MAJOR version when you make incompatible API changes
+        increment the MINOR version when you add functionality in a backward compatible manner
+        increment the PATCH version when you make backward compatible bug fixes
+
+  The most important thing is that if we change an API or command-line user
+  journey in a way that could break an existing use-case, we must increment the
+  major version.
+
+- Update the `action.yml` to change the `RELEASE_VERSION` variable to the new desired release version
+  and submit a pull request (this seems odd, but we want to reference the future version as it will
+  be built after we tag this commit).
+
+- After the pull request from the previous step is merged, push a signed tag in git, with
+  the tag named with your version number, with a
+  message saying why you're creating this release. For example:
+
+        $ git tag -s -a v0.2.7 -m 'Release v0.2.7'
+        $ git push origin v0.2.7
+
+- A GitHub workflow will be triggered by the tag push and will handle
+  everything. You will see the new release created within a few minutes. If not,
+  look for failed [Release workflow runs](https://github.com/abcxyz/secure-setup-terraform/actions/workflows/release.yml)
+  and look at their logs.

action.yml

@@ -57,7 +57,7 @@ runs:
     - name: 'secure-terraform'
       shell: 'bash'
       env:
-        RELEASE_VERSION: '0.2.4'
+        RELEASE_VERSION: '0.2.7'
         RELEASE_LOCATION: 'https://github.com/abcxyz/secure-setup-terraform/releases/download'
       run: |-
         ARCH="amd64";