Update '.drone.yml'

.drone.yml

@@ -5,13 +5,30 @@ name: ui
 steps:
 - name: build-ui
   image: node:12.7.0
+  volumes:
+  - name: build
+    path: /build/
   commands:
   - cd client
   - yarn install
   - yarn build
+  - mv build/* /build/
   when:
     branch:
     - master
+- name: test-volume
+  image: alpine/3.8
+  volumes:
+  - name: build
+    path: /build/
+  commands:
+  - cd /build/
+  - ls
+  - cat index.html
+    
+volumes:
+- name: build
+  temp: {}
 
 ---
 kind: pipeline