Publish tagged releases on GPR.

.github/workflows/ci.yml

@@ -25,3 +25,16 @@ jobs:
 
     - name: Runs code QA and tests
       run: rspec
+
+    - name: Publish to GPR
+      if: ${{ startsWith(github.ref, 'refs/tags/') }}
+      run: |
+        mkdir -p $HOME/.gem
+        touch $HOME/.gem/credentials
+        chmod 0600 $HOME/.gem/credentials
+        printf -- "---\n:github: Bearer ${GEM_HOST_API_KEY}\n" > $HOME/.gem/credentials
+        gem build
+        gem push --KEY github --host https://rubygems.pkg.github.com/${OWNER} *.gem
+      env:
+        GEM_HOST_API_KEY: ${{secrets.GPR_AUTH_TOKEN}}
+        OWNER: fast_jsonapi