restructure docker build a bit

Dockerfile

@@ -2,13 +2,13 @@ FROM node:alpine as files
 ENV TZ="Europe/Berlin"
 WORKDIR /app
 COPY [ "package-lock.json", "package.json", "index.ts", "tsconfig.json", "./" ]
-COPY server ./server
 
 FROM files as proddependencies
 ENV NODE_ENV=production
 RUN npm ci --omit=dev
 
 FROM proddependencies as compile 
+COPY server ./server
 RUN npm run build
 CMD ["npm","run","start"]
 
@@ -16,6 +16,7 @@ FROM files as dependencies
 RUN npm ci
 
 FROM dependencies as test
+COPY server ./server
 COPY jest.config.js .
 COPY tests ./tests
 RUN npm run test