[WIP] rspec3

Still following deprecated warnings are exist.

```
The `:example_group` key in an example group's metadata hash is deprecated. Use the example group's hash directly for the computed keys and `:parent_example_group` to access the parent example group metadata instead. Called from /Users/nikushi.nobuhiro/prj/yohoushi/spec/controllers/api/complexes_controller_spec.rb:3:in `<top (required)>'. 
```