Update docker file to node 8

Dockerfile

@@ -1,4 +1,4 @@
-FROM node:6.3
+FROM node:8
 
 ENV HOST localhost
 ENV PORT 3000
@@ -9,14 +9,13 @@ WORKDIR /usr/src/app
 
 # Install GYP dependencies globally, will be used to code build other dependencies
 RUN npm install -g --production node-gyp && \
-    cd $(npm root -g)/npm && npm install --production fs-extra && sed -i -e s/graceful-fs/fs-extra/ -e s/fs.rename/fs.move/ ./lib/utils/rename.js && \
-    npm cache clean
+    npm cache clean --force
 
 # Install app dependencies
 COPY package.json /usr/src/app
 RUN npm install --production && \
     npm install --production [email protected] [email protected] [email protected] pg && \
-    npm cache clean
+    npm cache clean --force
 
 # Bundle app source
 COPY . /usr/src/app