Adding another phase to pre-existing competition fails

[bbearce]

Creating a competition from scratch allows multiple phases, but adding one during an "update" is not working and produces an error.

Phases a and b were created upon challenge creation and attempting to add c is failing with error.

[bbearce]

This was created as a competition, not a benchmark. However the error suggests Codabench is attempting to save this update as a benchmark instead of a competition. This could explain why "creation" works and not "update". Perhaps during create, codabench saves as a competition.