Upgrade to ubuntu 18.04 and add in postgres

ak-ubuntu/Dockerfile

@@ -1,24 +1,24 @@
-FROM ubuntu:16.04
+FROM ubuntu:18.04
 
 LABEL maintainer "Appknox <engineering@appknox.com>"
 
 ENV GOSU_VERSION 1.10
 ENV LANG en_US.UTF-8
 
-RUN apt-get update -y || apt-get update -y \
+RUN apt-get update -y \
   && DEBIAN_FRONTEND=noninteractive apt-get install -y \
     build-essential \
     curl \
     git \
     zip \
     software-properties-common \
-    python-software-properties \
     fonts-noto-cjk \
     language-pack-en \
-  && curl -sL https://deb.nodesource.com/setup_9.x -o nodesource_setup.sh \
+  && curl -sL https://deb.nodesource.com/setup_10.x -o nodesource_setup.sh \
   && bash nodesource_setup.sh \
   && add-apt-repository ppa:nginx/development -y \
-  && add-apt-repository ppa:deadsnakes/ppa \
+  && curl -s https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add - \
+  && sh -c 'echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -cs)-pgdg main" > /etc/apt/sources.list.d/pgdg.list' \
   && apt-get update -y \
   && gpg --keyserver ha.pool.sks-keyservers.net --recv-keys B42F6819007F00F88E364FD4036A9C25BF357DD4 \
   && curl -o /usr/local/bin/gosu -SL "https://github.com/tianon/gosu/releases/download/$GOSU_VERSION/gosu-$(dpkg --print-architecture)" \