v0.2.1

FLOWMath v0.2.1

Diff since v0.2.0

Merged pull requests:

• Install TagBot as a GitHub Action (#8) (@JuliaTagBot)
• Akima gradient (#9) (@taylormcd)
• minor fixes to allow dual numbers to propgate through (#10) (@andrewning)
• linear interpolation (#11) (@andrewning)