Test of changes to MDL CDL file (#20)

* Adding a test CDL file from MDL.  Added tests for MDL process chain CDL file.

Author: jjlevit

lib/bald/tests/integration/CDL/ProcessChain0300.cdl

@@ -0,0 +1,27 @@
+netcdf tmpcdltest {
+variables:
+        int gfsmos_process_chain;
+        gfsmos_process_chain:OM_Process = "(step1 step2)";
+
+int step1;
+        step1:LE_ProcessStep = "NWP__/Models/GFS13" ;
+        step1:LE_Source = "DA__/Methods/GDAS13" ;
+
+int step2 ;
+        step2:LE_ProcessStep = "StatPP__/Methods/GFSMOS05" ;
+        step2:LE_Source = "NWP__/Models/GFS13" ;
+
+//global attribute
+        :process_chain = "gfsmos_process_chain";
+        :bald__isPrefixedBy = "prefix_list" ;
+
+group: prefix_list {
+
+// group attributes:
+        :DA__ = "https://codes.nws.noaa.gov/DataAssimilation" ;
+        :NWP__ = "https://codes.nws.noaa.gov/NumericalWeatherPrediction" ;
+        :StatPP__ = "https://codes.nws.noaa.gov/StatisticalPostProcessing" ;
+        :bald__ = "http://binary-array-ld.net/latest/" ;
+      
+  } // group bald__prefix_list
+}

lib/bald/tests/integration/test_cdl.py

@@ -28,3 +28,11 @@ def test_alias(self):
             validation = bald.validate_netcdf(tfile)
             exns = validation.exceptions()
             self.assertTrue(validation.is_valid(), msg='{}  != []'.format(exns))
+            
+    def test_process_chain(self):
+        with self.temp_filename('.nc') as tfile:
+            cdl_file = os.path.join(self.cdl_path, 'ProcessChain0300.cdl')
+            subprocess.check_call(['ncgen', '-o', tfile, cdl_file])
+            validation = bald.validate_netcdf(tfile)
+            exns = validation.exceptions()
+            self.assertTrue(validation.is_valid(), msg='{}  != []'.format(exns))