If the username or password only contain digits, the ruby_fints library chokes because the YAML-parser returns the username/password as integer, while ruby_fints expects strings.

Thanks to @peterjeschke for fixing a bug that happened when the FinTS username was an integer

This commit cleans up the README.md file and references the dumper notes to understand the limitations of each dumper

)

Because the values that we get from the (not official) N26 API change from time to time, people often end up with duplicated transactions.

This code change introduced a new config flag for the N26 Dumper called skip_pending_transactions.

Fixes #52

The old API still works and might be supported, but it's in the
deprecated section of the docts and but POST to transactions should be
more "future-proof" according to the 2018-10-04 release notes:

https://www.youneedabudget.com/release-notes/#release_81452

So rebuilding the image isn't needed for development