Create tenant directory structures

* Move controllers & views
Namespace controllers to Tenants::
Add tenants controller
Configure router with tenant namespace
Add index method, routing appears to work
Add tenants model
Move the index to tenants
Add basic index to tenants controller
Fix model validations / relationships
Fix namespacing for global tenant views

* All users can view all tenants

* Namespace is reflected here.

* Closes #54
Remove offending empty spec
Merge pull request #58 from bayendor/54_basic_tenancy

54 basic tenancy