add dockerfile

Dockerfile

+FROM pubsweet/pubsweet:base
+
+COPY package.json yarn.lock ./
+COPY lerna.json .eslintignore .eslintrc .prettierrc .stylelintignore .stylelintrc ./
+COPY packages packages
+
+RUN [ "yarn", "config", "set", "workspaces-experimental", "true" ]
+
+# We do a development install because react-styleguidist is a dev dependency
+RUN [ "yarn", "install", "--frozen-lockfile" ]
+
+# Remove cache and offline mirror
+RUN [ "yarn", "cache", "clean"]
+RUN [ "rm", "-rf", "/npm-packages-offline-cache"]
+
+ENV NODE_ENV "production"
+
+WORKDIR ${HOME}/packages/ui
+RUN [ "npm", "run", "styleguide:build" ]
+# Create file for kubernetes health checks
+RUN touch ./styleguide/health
+
+EXPOSE 3000
+
+WORKDIR ${HOME}
+CMD []