South Pole Observatory data

[rhyolight]

lots of stuff there: http://www.esrl.noaa.gov/gmd/dv/data/index.php?site=spo

[rhyolight]

Here's one:

• ftp://aftp.cmdl.noaa.gov/data/meteorology/in-situ/README (data description)
• ftp://aftp.cmdl.noaa.gov/data/meteorology/in-situ/spo/met_spo_insitu_1_obop_hour_2015.txt (data for 2015).

There is a standard directory structure so when the year rolls over the url could change. Depends on #105 because of FTP.

The way this data is aggregated yearly means that this might depend on #104. And also, we may need a more complex way to generate the source URLs. Currently, they can be hard-coded in the config or the river initializer function can return them, but that only gets called on River View startup.