v0.3.0 Kelly

Release before a round of big refactorings.

Changes:

• Offboard example added (#116)
• Added fields to info (#118)
• Mavlink statustexts added for debugging (#119)
• Fixed RC status bug (#123)
• Gimbal plugin added (#124)
• Support for .deb and .rpm packages (#130, #196, #198)
• Add support for delays before camera actions (#131)
• Simplify offboard usage (#134)
• Follow me plugin added (#142, #199)
• gRPC work (#143, #174, #175)
• Support to download mission (#145)
• Use fake time for unit tests (#147)
• VTOL transition support (#150, #163)
• Fix 100% CPU bug for serial connections (#177)