updating node versions and fixing result tests

result/Dockerfile

@@ -1,4 +1,4 @@
-FROM node:5.11.0-slim
+FROM node:8.9-slim
 
 WORKDIR /app
 

result/tests/Dockerfile

@@ -1,5 +1,11 @@
-FROM node
-RUN npm install -g phantomjs
+FROM node:8.9-slim
+RUN apt-get update -qq && apt-get install -qy \
+    ca-certificates \
+    bzip2 \
+    curl \
+    libfontconfig \
+    --no-install-recommends
+RUN yarn global add phantomjs-prebuilt
 ADD . /app
 WORKDIR /app
 CMD ["/app/tests.sh"]