ENH: microburst data

[jklenzing]

Is your feature request related to a problem? Please describe. Add microburst data from FIREBIRD and RBSP.

Describe the solution you'd like

• FIREBIRD has both regular data (cdf) and hires (txt), and is archived at university of montana via html. Should be able to use standard interface with custom top url.
• RBSP is in cdf and should use the standard pysatNASA interface

Describe alternatives you've considered 😿

Additional context

• http://solar.physics.montana.edu/FIREBIRD_II/Data/FU_3/hires/
• http://rbsp.space.umn.edu/firebird/
• https://spdf.gsfc.nasa.gov/pub/data/rbsp/

[jklenzing]

Bumping this to an unspecified future milestone for now

[jklenzing]

RBSP has two names! The files and such are all labeled rbsp, the cdaweb front end uses van allen probes.