BUG: Monthly file download

[aburrell]

Describe the bug
Currently, it looks like pysatNASA is getting the level 3a files from the 'CDF' directory on CDAWeb, but this means that a chunk of the data is missing.

To Reproduce
Compare: https://cdaweb.gsfc.nasa.gov/pub/data/timed/see/data/level3a_cdf/2008/11/

to

https://cdaweb.gsfc.nasa.gov/pub/data/timed/see/data/level3a/2008/

Expected behavior
There would not be data gaps based on the source

Additional context
This is likely a CDAWeb issue.

[jklenzing]

Linking to #14, #103. TIMED SEE needs an overhaul anyway.

Looking at my local file structure, the cdf files are monthly versions of the daily netcdf files

[jklenzing]

Also linking to #104, since the netCDF support issues there apply here as well.

[aburrell]

Ok, so the real issue is that the download routine doesn't adjust the start date correctly for monthly data. This is an issue with the download function that should be fixed, since a user should not be required to know the download file cadance.

[jklenzing]

Verified that this was fixed by #145.