Publish API Docs to GH Pages when merging to master

[felippenardi]

Summary

This circleci config will ensure that:

• Tests run for every commit made in a branch that is not develop
• API Docs are generated and published as a GH Page when a branch is merged to develop

Required steps before merging:

1. Create a clean gh-pages branch following these steps:
2. Follow the steps on deployment-circleci-gh-pages skipping the circle.yml and deploy.sh configuration

Solves: https://github.com/kleros/kleros-store/issues/16

[n1c01a5]

@felippenardi I have some troubles with the circle-ci build see https://circleci.com/gh/kleros/kleros-store/24 have you any idea

[felippenardi]

@n1c01a5 Looks like a missing github authentication setup on CirleCI, but I see you just figured it out :) 👏