0.3.7

- [X] Use `defconst` keyword instead of defvar
- [X] Use trello labels and org tags as one - CLOSE https://github.com/org-trello/org-trello/issues/70
- [X] Refactor + Fix create / connect to board
- [X] Update metadata command about the board currently connected (sometimes, new information arise)
- [X] Release notes
- [X] Version