Truncate OAuth key and secret in list view

OAuth keys and secrets can be really long (i.e. with Google's OAuth 2). This causes the list of authentication methods to grow too big horizontally. Truncating the keys solves this issue.

Fixes #73
Log instead of print loading of authentication source

Which authentications sources get loaded during initialization is informational and should be logged as such - and not written to stdout.
Yaml lint locales.
Refactor for Spree 2.0.

- Cleanup and code formatting.
- 1.9 hash syntax.
- Build statuses.
- Simplecov, coveralls and gemnasium.
- Locale tests.