Add train snapshot build

.github/workflows/build-snapshot-worker.yml

+# Worker which is dispatched from build-snapshot-controller workflow.
+name: Build Snapshot Worker
+
+on:
+  workflow_dispatch:
+    inputs:
+      build-zoo-handler:
+        description: 'Build Zoo Handler Payload'
+        required: true
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+
+    - uses: actions/checkout@v2
+    - uses: actions/setup-java@v1
+      with:
+        java-version: 1.8
+    - uses: jvalkeal/setup-maven@v1
+      with:
+        maven-version: 3.6.3
+    - uses: jfrog/setup-jfrog-cli@v1
+      with:
+        version: 1.43.2
+      env:
+        JF_ARTIFACTORY_SPRING: ${{ secrets.JF_ARTIFACTORY_SPRING }}
+
+    # target deploy repos
+    - name: Configure JFrog Cli
+      run: |
+        jfrog rt mvnc \
+          --server-id-resolve=repo.spring.io \
+          --server-id-deploy=repo.spring.io \
+          --repo-resolve-releases=libs-release \
+          --repo-resolve-snapshots=libs-snapshot \
+          --repo-deploy-releases=release \
+          --repo-deploy-snapshots=snapshot
+        echo JFROG_CLI_BUILD_NAME=spring-cloud-deployer-local-main >> $GITHUB_ENV
+        echo JFROG_CLI_BUILD_NUMBER=$GITHUB_RUN_NUMBER >> $GITHUB_ENV
+
+    # zoo extract and ensure
+    - name: Extract Zoo Context Properties
+      uses: jvalkeal/build-zoo-handler@v0.0.4
+      with:
+        dispatch-handler-extract-context-properties: true
+
+    # build and publish to configured target
+    - name: Build and Publish
+      run: |
+        jfrog rt mvn -U -B clean install
+        jfrog rt build-publish
+        echo BUILD_ZOO_HANDLER_spring_cloud_deployer_local_version=$(mvn help:evaluate -Dexpression=project.version -q -DforceStdout) >> $GITHUB_ENV
+        echo BUILD_ZOO_HANDLER_spring_cloud_deployer_local_buildname=spring-cloud-deployer-local-main >> $GITHUB_ENV
+        echo BUILD_ZOO_HANDLER_spring_cloud_deployer_local_buildnumber=$GITHUB_RUN_NUMBER >> $GITHUB_ENV
+
+    # zoo success
+    - name: Notify Build Success Zoo Handler Controller
+      uses: jvalkeal/build-zoo-handler@v0.0.4
+      with:
+        dispatch-handler-token: ${{ secrets.SCDF_ACCESS_TOKEN }}
+        dispatch-handler-client-payload-data: >
+          {
+            "event": "build-succeed"
+          }
+
+    # zoo failure
+    - name: Notify Build Failure Zoo Handler Controller
+      if: ${{ failure() }}
+      uses: jvalkeal/build-zoo-handler@v0.0.4
+      with:
+        dispatch-handler-token: ${{ secrets.SCDF_ACCESS_TOKEN }}
+        dispatch-handler-client-payload-data: >
+          {
+            "event": "build-failed"
+          }