Added rspec
Added basic spec that the import still works, including a example Saldomat RSS file.
Added fuubar gem for prettier rspec output
Moved Saldomat account importer to separate file and made the account importer configurable.

- Moved import of Saldomat feed to AccountImporter::Saldomat
- added a dummy HBCI importer
- store the importer class name on the account model, default is set to Saldomat.
Fixed AccountImporter::HBCI interface.