Make a PR (Pull-Request) on this repository that fixes this code.
It will be automatically validated by Travis CI (Continuous Integration), so if it’s green you already have a good grade. I will give you extra points if you succeed to reduce the size of the codebase without breaking it!
You can test your code by trying to decrypt this secret message:
RW4gYmlvbG9naWUgZGUgbCfDqXZvbHV0aW9uLCBsYSBjYXJjaW5pc2F0aW9uIGVzdCB1biBleGVtcGxlIGRlIGNvbnZlcmdlbmNlIMOpdm9sdXRpdmUsIGFtZW5hbnQgcGx1c2lldXJzIGVzcMOoY2VzIGRlIGNydXN0YWPDqXMgbm9uIGFwcGFyZW50w6llcyDDoCDDqXZvbHVlciB2ZXJzIGRlcyBmb3JtZXMgcmVzc2VtYmxhbnQgw6AgZGVzIGNyYWJlcy4gTGUgdGVybWUgZnV0IGludHJvZHVpdCBwYXIgQWxleGFuZGVyIEJvcnJhZGFpbGUsIGxlIGTDqWZpbmlzc2FudCBjb21tZSDCqyB1bmUgZGVzIG5vbWJyZXVzZXMgdGVudGF0aXZlcyBkZSBsYSBOYXR1cmUgcG91ciBjcsOpZXIgdW4gY3JhYmUgwrsuIA==