Merge pull request #390 from sterlingbaldwin/master

Fixes crash while running ocean_add_depth

This merge fixes an if clause that I believe to be backwards.

Author: xylar

conda_package/mpas_tools/ocean/depth.py

@@ -111,7 +111,7 @@ def add_depth(inFileName, outFileName, coordFileName=None):
         An MPAS-Ocean file with ``refBottomDepth``
     """
 
-    if coordFileName is not None:
+    if coordFileName is None:
         coordFileName = inFileName
 
     ds = xarray.open_dataset(inFileName, mask_and_scale=False)