list of "finished" card saved with an extra ,

[Alessio Basso]

If you erroneously click on "add list" in the sprint edit page without typing anything in the list name textbox, a empty list will be added to the list of lists ( ;) ); upon clicking Save, the list names are stored in the config json anyway.

When a generation is attempted, and a list named "" (empty string) is in the config json, the generation fails (as there can't be a trello list named "").

Example of json config with first list is named "":

{
    "lists": ",In progress,Known issues/deferred,Testing",
    "days": [
[...]

[Alessio Basso]

Fixed by merging #27