Added node-phantomjs dockerfile for projects like droplab, with no need for git or ruby

Dockerfile.node-7.1-phantomjs-2.1

+FROM node:alpine
+
+ADD / /
+RUN /scripts/install-essentials
+RUN /scripts/install-phantomjs 2.1.1
+
+RUN locale-gen en_US.UTF-8
+ENV LANG en_US.UTF-8
+ENV LANGUAGE en_US:en
+ENV LC_ALL en_US.UTF-8