Improve coverage

[hadim]

Especially in sktracker.trajectories.measures :-)

sktracker.detection.nuclei_detector                         168     24    86%   84, 117, 120, 126-127, 131-138, 144-147, 149, 183-185, 187-188, 252, 254-255, 259, 300-30

sktracker.trajectories.measures.measure_decorators           24      2    92%   42, 48
sktracker.trajectories.measures.rotation                    122     30    75%   20-25, 34-35, 71-72, 125-126, 139-156, 179-182, 241-245, 249
sktracker.trajectories.measures.transformation              104     13    88%   33, 43-46, 52, 56, 133-137, 270

Minimim coverage for a single module/file should be 90% in my opinion.

[hadim]

I will take care of sktracker.io.ome.

sktracker.io.ome                                            169     28    83%   111-112, 120-121, 127, 137-139, 144-148, 166-184, 268