Openruko business process to register addon

Documentation here https://github.com/azukiapp/apiserver/wiki/Openruko-Addons
By default, when you register an addon, test plan is created and the addon is
available as 'beta' version.

List all available add-ons

GET /addons

Defining price as object on addon list

Removing heroku_addons view

Openruko business process to register addon

Renaming oraddon to addon
Pre-version addons:add support
Support to addons:add command

Use Heroku's pattern addons:add.
More info about API documentation, here https://github.com/azukiapp/apiserver/wiki/Openruko-Addons

Remove needless workaround
Temporary workaround to make life easier when registering add-ons
Make create_release save addons info
Validate if addon already on release
Removing param not used from get_app_addon proc
Check response from provider
Fix check if addon already installed
Tests for addons:add
Set timeout of 1s when requesting resources
Tiny refactoring on addon tests
Change column addon_id and plan_id to name
Created table app_addon to save resource info
Support to addons:remove command

Use Heroku's pattern addons:remove.
More info about API documentation, here https://github.com/azukiapp/apiserver/wiki/Openruko-Addons
Merge pull request #29 from azukiapp/addons

Add-ons following Heroku's pattern