Shender/samson 107 autorefresh current deploys


Describe your PR

This PR is primarily for discussion purposes and is in no way ready for merging. It is related to issue #177 where we voted to move more fully to angular on the frontend, and leave the rails app as more of an API.

The file structure for the javascript is the traditional AngularJS and not the newer (e.g. egghead.io) one which incorporates the templates and groups files in terms of area rather than functionality, so:
- controllers
- filters
- directives
- services

I moved the relevant views (active.html.erb, recent.html.erb, ..) over to /public/templates where they can be retrieved on-demand by the angular engine.

To get push notifications I setup a basic Radar (https://github.com/zendesk/radar) installation, and used the Radar Client Gem (currently private in Zendesk). 
Configuration settings are stored in the .env file and accessed by both the NodeJS Radar app, and the Rails app.

I basically reorganized both the 'Recent Deploys' and 'Current Deploys' pages because they share most of their functionality.

Anyway, I will appreciate the feedback. Obviously I'll be adding tests as soon as it's clear I don't have to completely re-implement things.

/cc @zendesk/samson, @pswadi-zendesk 

### References
 - Jira link:

### Risks
 - None
Weird that it's not there already. Can see it got added in https://github.com/zendesk/zendesk_samson/pull/392