Update ci config and add Dockerfile for running App in local

[ganezasan]

Hi, I added some changes for improving this project.

• update circleci config
  • add workflow
  • use Anchor/Alias of YAML function
• add Dockerfile for running App in local
• change the root path in App
• update ruby version 2.4.2 to 2.6.3
• update rails version 5.1.4 to 5.2.3

[lokst]

It might be good to update the year in Copyright (c) 2017 CircleCI too

[ganezasan]

@lokst Thanks! I update the Copyright to 2019 :) @BoVice I updated the config to 2.0. And added some fixes. could you review it?