Update Dockerfile.

Dockerfile-prod

@@ -1,15 +1,14 @@
-FROM python:3.5
-RUN apt-get update
-RUN apt-get install -y nodejs npm
-RUN ln -s /usr/bin/nodejs /usr/bin/node
+FROM python:3.6
+RUN apt-get install curl
+RUN curl -sL https://deb.nodesource.com/setup_6.x | bash -
+RUN apt-get install -y nodejs
 RUN mkdir /code
 WORKDIR /code
 RUN mkdir requirements
 ADD bikeshop_project /code
 COPY requirements /code/requirements
 RUN pip install -r requirements/production.txt
-WORKDIR /code/bikeshop_project
-rm node_modules
-RUN npm clean cache
+RUN npm cache clean
+RUN npm install --unsafe-perm
 RUN npm run build-production
 RUN DJANGO_SETTINGS_MODULE=bikeshop.settings.production python manage.py collectstatic --no-input