Change versioning to 0.xx.x to denote alpha state

[andrewjong]

AirStack is still very much an alpha state. To avoid confusion, let's change the versioning to 0.xx.x; 1.x.x should only be when we're confident it's run live in the field and has all the core features we want. Currently AirStack is still missing many things

• reliable VIO
• multiagent
• proper comms
• proper ground control with TAK
• common hardware workflow
• automated testing, CI/CD
• independent dynamics from Ascent AeroSystems, should switch to Pegasus to actually interact with the world
• support different types of robots, e.g. other flying robots, ground robots
• more simulation environments
• make public access for AirLab docker registry
• experimental logging and playback workflow
• GUI improvements

[andrewjong]

Addressed in b2f3250