Added new dockerfile for plugin development

Dockerfile

@@ -5,16 +5,20 @@ RUN mkdir -p /usr/src/app
 WORKDIR /usr/src/app
 
 # Setup the environment
-ENV NODE_ENV production
 ENV PATH /usr/src/app/bin:$PATH
 ENV TALK_PORT 5000
 EXPOSE 5000
 
-# Install app dependencies
-COPY package.json yarn.lock /usr/src/app/
-RUN yarn install --production
-
 # Bundle app source
 COPY . /usr/src/app
 
+# Install app dependencies and build static assets.
+RUN yarn install && \
+    yarn build && \
+    yarn install --production && \
+    yarn cache clean
+
+# Ensure the runtime of the container is in production mode.
+ENV NODE_ENV production
+
 CMD ["yarn", "start"]