Additional test cases for isogram #71
Description
Few additional tests were added to isogram exercise in canonical data:
- Isogram: add test for duplicate if the second is upper case problem-specifications#1307
- Isogram: add test for duplicate if the second is upper case problem-specifications#1307
These are recent few changes, but our tests might be lacking some more changes (I did not check). The task is to make the tests in this track in sync with the canonical data. Add tests and make changes to example solution if required.