Add publish job to ci workflow

Author: michaelbull

.github/workflows/ci.yaml

@@ -1,9 +1,9 @@
 name: ci
 
-on: [push, pull_request]
+on: [ push, pull_request ]
 
 jobs:
-  build:
+  check:
     runs-on: ubuntu-latest
 
     steps:
@@ -28,3 +28,37 @@ jobs:
           java-version: 1.8
 
       - run: ./gradlew check
+
+  publish:
+    needs: check
+    if: github.ref == 'refs/heads/master' && github.event_name == 'push' && needs.check.result == 'success'
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: actions/cache@v1
+        with:
+          path: ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-wrapper-${{ hashFiles('gradle/wrapper/gradle-wrapper.*') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-wrapper-
+
+      - uses: actions/cache@v1
+        with:
+          path: ~/.gradle/caches
+          key: ${{ runner.os }}-gradle-caches-${{ hashFiles('**/*.gradle.kts') }} }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-caches-
+
+      - uses: actions/setup-java@v1
+        with:
+          java-version: 1.8
+
+      - run: ./gradlew publish
+        env:
+          ORG_GRADLE_PROJECT_ossrhUsername: ${{ secrets.OSSRH_USERNAME }}
+          ORG_GRADLE_PROJECT_ossrhPassword: ${{ secrets.OSSRH_PASSWORD }}
+          ORG_GRADLE_PROJECT_signingKeyId: ${{ secrets.SIGNING_KEY_ID }}
+          ORG_GRADLE_PROJECT_signingKey: ${{ secrets.SIGNING_KEY }}
+          ORG_GRADLE_PROJECT_signingPassword: ${{ secrets.SIGNING_PASSWORD }}