Post tournament

Allow the backend to create a new fresh tournament.

added backend label

added To Do label

added Doing label

assigned to @tobiasio

removed To Do label

created merge request !11 (merged) to address this issue

mentioned in merge request !11 (merged)

mentioned in commit 35ed2b61

closed via merge request !11 (merged)

mentioned in commit 7298561d

removed Doing label