coops: Differentiate between empty region and no region input

[SorooshMani-NOAA]

Fixes #60

[SorooshMani-NOAA]

@pmav99, from the ticket perspective the fix is done. The test errors here seem to be related to USGS server failure in SSL cert verification. Related to DOI-USGS/dataretrieval-python#100

[SorooshMani-NOAA]

@pmav99 the USGS server issue is resolved. But the remaining tests fail due to the same IOC NA issue: #91

[pmav99]

@SorooshMani-NOAA I am on leave for a few days. If it is not too much trouble, please apply this patch: #91 (comment)

[SorooshMani-NOAA]

@pmav99 sure, thanks

[codecov]

Codecov Report

Merging #92 (a225974) into master (1309683) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master      #92   +/-   ##
=======================================
  Coverage   90.16%   90.17%           
=======================================
  Files          13       13           
  Lines        1007     1008    +1     
  Branches      148      148           
=======================================
+ Hits          908      909    +1     
  Misses         54       54           
  Partials       45       45           

Impacted Files	Coverage Δ
searvey/coops.py	84.30% <100.00%> (ø)
searvey/stations.py	100.00% <100.00%> (ø)