Use RSpec as test lib
Remove obsolete test unit files
Statement gets its own class
Begin with integration tests
Transaction gets its own class
File#valid? and File#errors
Use Object#try from active_support
Make default country configurable
Transaction data integration test
Use class for amount calculation
More integration tests
Use BigDecimal for amount
Handle non-XML files
New method Transaction#purpose
Add sample file from Germany (Commerzbank) with test
Merge pull request #2 from cpetschnig/master

Various improvements and refactorings