CohenBerkeleyLab/BEHR-core: Version 3.0B

Changes from version 3.0A to 3.0B include:

• Change in ocean reflectivity LUT from 430 nm to 460 nm
• Implementation of variable tropopause pressure
• Fix so that AMFs and VCDs are set to NaN/fill value if any of the NO2

       profile, clear or cloudy scattering weights, or temperature profiles
       are all NaNs for that pixel
  

• Cloud pressure clamped to <= surface pressure for the AMF calculation,

       this deals with an issue where the NO2 profile can have NaNs in it during
       the calculation of the cloudy AMF because it was not extrapolated far
       enough to reach to cloud pressure. Also, physically, cloud top should not
       be below the surface.