Add workflow to publish snapshots from production branches

Author: DanielThomas

.github/workflows/nebula-snapshot.yml

@@ -0,0 +1,39 @@
+name: "Publish snapshot to NetflixOSS and Maven Central"
+
+on:
+  push:
+    branches:
+      - master
+      - 'release/**'
+      - 'feature/**'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: Set up JDK
+        uses: actions/setup-java@v1
+        with:
+          java-version: 8
+      - uses: actions/cache@v2
+        id: gradle-cache
+        with:
+          path: |
+            ~/.gradle/caches
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle') }}
+      - uses: actions/cache@v2
+        id: gradle-wrapper-cache
+        with:
+          path: |
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradlewrapper-${{ hashFiles('gradle/wrapper/*') }}
+      - name: Build
+        run: ./gradlew build snapshot
+        env:
+          NETFLIX_OSS_SIGNING_KEY: ${{ secrets.ORG_SIGNING_KEY }}
+          NETFLIX_OSS_SIGNING_PASSWORD: ${{ secrets.ORG_SIGNING_PASSWORD }}
+          NETFLIX_OSS_REPO_USERNAME: ${{ secrets.ORG_NETFLIXOSS_USERNAME }}
+          NETFLIX_OSS_REPO_PASSWORD: ${{ secrets.ORG_NETFLIXOSS_PASSWORD }}