Danger bot boilerplate

[jonduran3000]

• Added boilerplate to provide automated code review comments on PRs
  • Gemfile to download all the Danger dependencies
  • A python script to merge all of the ktlint reports
  • Dangerfiles to send lint/ktlint issues to the Github bot
  • Updated the CircleCI YAML script
• Updated the README with an additional instruction

[jonduran3000]

For reference: https://blog.bitrise.io/automating-code-review-tasks-for-multi-module-android-projects