Restructure tests

* Move unit tests to spec/unit
* Move integration tests to spec/features
* Compatibility with netzke-testing 0.9.2
More filter specs
Rewrite custom primary key spec
Remove tests for "nested attributes"

Don't plan to support those any longer
Rewrite i18n tests
Rewrite specs for region persistence
Remove SimpleApp

Do not plan supporting it
Clean-up old test code
Move old testing components out to example dir
Keep version in Basepack::VERSION string
Update dependencies
Prepare 0.10.0.rc1
Prepare 0.10.0.rc2