[ADD] build back job

.github/workflows/build_back.yml

@@ -0,0 +1,22 @@
+name: Build_Back
+
+on:
+  workflow_call:
+
+jobs:
+
+## Build Back ##
+
+  Build_Back:
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    defaults:
+      run:
+        working-directory: ./back
+    environment: Staging
+
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Build Docker
+        run: docker build -t testback .