fix test
Implement GET /v3/apps/:guid

[#79386466]
Added POST request for /v3/apps

[#79386466]
DELETE endpoint for v3 apps

[#79386466]
Refactored processes api spec to use match.

[#79386466]
Remove integrationy tests from processes controller
Added v3 api to create a process for a given app.

[#79386466]
Added process links to v3 app api.

[#79386466]
Whitespace.

[#79386466]
Lock down user_visible for app_model

[#79386466]
Creating /v2/apps will create a parent /v3/apps

[#79386466]
Deleting a space deletes the v3 apps associated to it

[#79386466]
Added "/v3/processes" resource endpoint.

 - Validate that process receives an app_guid on creation.

[#79386466]
Prevent deletion of apps that have child processes

[#79386466]
Prevent deletion of spaces with a v3 app associated to it without recursive=true

[#79386466]
Add PUT /v3/apps/:guid/processes to associate a process with an app

 - Refactor ProcessesController to call to ProcessesHandler, which is
 responsible for dealing with request bodies and raising the appropriate
 API errors when necessary.
 - New AppRepository to handle interactions with apps_v3

[#79386466]
remove process_repository dependency from app_repository
use existing dependency injection pattern in appv3 controller
Refactor ProcessHandler to move most of the api logic out

[#79386466]
Implement GET /v3/apps/:guid/processes and DELETE /v3/apps/:guid/processes

* You can view the associated processes if you can view the app
* Eager load spaces and stacks when fetching associated processes
* Disassociating a process form an app will associate it to nothing

[#79386466]