**Features**:
- add amount `amount_original` ("ursprünglicher Betrag") field to creditcard transaction list
**Improvements**:
- adding code-review badge from [lgtm.com](https://lgtm.com/projects/g/grindsa/dkb-robo/?mode=list)
- some smaller fixes to address [lgtm code-review comments](https://lgtm.com/projects/g/grindsa/dkb-robo/alerts/?mode=list)