[Needs Review] Auto Generated Swagger docs and new docs site on Github Pages

[darahayes]

This PR does a number of things,

1. docs/udaru-swagger-site is checked into source control. So the site generated by the newly added npm run swagger-gen is now saved in the repo.

2. A new script - scripts/deploy-gh-pages.sh This script is run during a travis build. It regenerates the swagger docs and if there are any changes, they are committed and pushed to master.

3. Some changes in the .travis.yml file to run the new script. This new config takes advantage of a new feature in travis called build stages. This allows us to run that publish script once only after the two separate builds for node 6 and node 7 are run.

4. Proposed Docs site - darahayes.github.io/udaru. Github Pages allows us host a docs site within the docs folder of the master branch. We already have a docs folder in the Udaru repo so I used a tool called docsify to turn our docs folder into that docs site in the link.

docsify some really nice features:

• There is no build process. It's essentially a SPA that renders the actual markdown files on the fly. Take a look at the docs/index.html file included in this PR.
• Navigation/Structure is incredibly simple. The sidebar you see in that demo site is defined using a single markdown file docs/_sidebar.md
• Super low effort and low investment - That site was made possible with a single html file and a markdown file (sidebar). Nothing else in the repo had to change to accommodate this. It also means we can get rid of it really easily if we want.

And btw you can go into the demo website here darahayes.github.io/udaru and then click the link in the sidebar to get the Swagger Docs.

I know there's going to be a big overhaul with the docs but I think this could really help.

Please let me know what you think.

[coveralls]

Coverage remained the same at 96.253% when pulling 6b6af6e on darahayes:master into 87a5c61 on nearform:master.

[dberesford]

This is really great step forward Dara, good job! I really like docsify, and also great there will be a ghpages for Udaru. I think we need to work on the documentation itself, and also on the swagger output, it doesn't really suit a static site (e.g. removing the 'Try it out' buttons), but overall this gives us a really solid foundation to make those changes from here.

[dberesford]

This can be removed. This file has been replaced by overview.md and I forgot to remove it in my last PR. Note PR to remove it here: #405

[dberesford]

Please change to 'Udaru - the Platform Authorization Service'

[coveralls]

Coverage remained the same at 96.253% when pulling 321d86b on darahayes:master into 87a5c61 on nearform:master.

[darahayes]

@dberesford I fully agree. The content of the docs really needs to be improved. I think before it was hard to know even where to begin but the little docsify site really helps us visualise the docs and gives us some structure to help make those decisions. Now we're in a great place to start improving.

I've made your changes as requested.

[coveralls]

Coverage remained the same at 96.253% when pulling 99e3149 on darahayes:master into 87a5c61 on nearform:master.

[coveralls]

Coverage remained the same at 96.253% when pulling 321d86b on darahayes:master into 87a5c61 on nearform:master.