[felix,sett] add phantomjs binary to image

see:
sgerrand/alpine-pkg-glibc#13 (comment)

Dockerfile

@@ -2,9 +2,14 @@ FROM alpine:3.5
 MAINTAINER the-mast@thoughtworks.com
 
 RUN apk add --update --no-cache gcc g++ make git curl 
-RUN apk add --update --no-cache python nodejs 
-RUN apk add --update --no-cache php5 php5-curl php5-openssl php5-json php5-phar php5-dom
+RUN apk add --no-cache python nodejs 
+RUN apk add --no-cache php5 php5-curl php5-openssl php5-json php5-phar php5-dom
 RUN npm install -g gulp-cli bower node-sass
+RUN apk add --no-cache fontconfig && \
+  mkdir -p /usr/share && \
+    cd /usr/share \
+      && curl -L https://github.com/Overbryd/docker-phantomjs-alpine/releases/download/2.11/phantomjs-alpine-x86_64.tar.bz2 | tar xj \
+        && ln -s /usr/share/phantomjs/phantomjs /usr/bin/phantomjs
 RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/bin --filename=composer
 
 CMD ["/bin/sh"]