add webpack step to .drone.yml test-build pipeline

.drone.yml

@@ -25,6 +25,14 @@ steps:
   commands:
     - dotnet restore
 
+- name: webpack
+  pull: always
+  image: mcr.microsoft.com/dotnet/core/sdk:3.1-alpine
+  depends_on: [clone]
+  commands:
+  - apk add --no-cache make git nodejs npm
+  - make webpack
+
 - name: debug
   pull: always
   image: mcr.microsoft.com/dotnet/core/sdk:3.1-alpine
@@ -41,7 +49,7 @@ steps:
   volumes:
   - name: pkgcache
     path: /root/.nuget/packages
-  depends_on: [restore]
+  depends_on: [restore, webpack]
   commands:
     - dotnet publish -c Release -o out