Version 1.6 - Automatic test and pixi file. With GEFF IO, start interface, pixi fixed

Added the option to import/export to TrackMate and GEFF format.
THe starting interface is now split in two steps: loaded raw movie then choice of metadata and type of segmentation, to make it clearer and integrate import from GEFF.
Pixi should be fixed for when cmake is not installed in the system.

What's Changed

• Add automatic tests by @gletort in #14
• Add GEFF import/export optins by @lxenard in #15, #16

Full Changelog: 1.5.3...v1.6