fix(docker): more efficient dockerfile for changes strictly to packag…

…es.json or bowerr.json

Dockerfile

@@ -33,12 +33,13 @@ WORKDIR /opt/mean.js
 # and utilities docker container cache to not needing to rebuild
 # and install node_modules/ everytime we build the docker, but only
 # when the local package.json file changes.
+# Install npm packages
 ADD package.json /opt/mean.js/package.json
+RUN npm install --quiet
+
+# Install bower packages
 ADD bower.json /opt/mean.js/bower.json
 ADD .bowerrc /opt/mean.js/.bowerrc
-
-# Install MEAN.JS packages
-RUN npm install --quiet
 RUN bower install --quiet --allow-root --config.interactive=false
 
 # Share local directory on the docker container