TST: update instrument tests

Update the instrument tests.  If `supported_tags` is not present, do not require it.  It is only required if the Instrument has 'cdf' files.

pysatNASA/tests/test_instruments.py

@@ -50,11 +50,12 @@
 skip_cdf_list = ['de2_vefimagb']
 
 for inst in instruments['download']:
-    fname = inst['inst_module'].supported_tags[inst['inst_id']][inst['tag']]
-    if '.cdf' in fname:
-        temp_inst, _ = clslib.initialize_test_inst_and_date(inst)
-        if temp_inst.pandas_format and temp_inst.name not in skip_cdf_list:
-            instruments['cdf'].append(inst)
+    if hasattr(inst['inst_module'], 'supported_tags'):
+        fname = inst['inst_module'].supported_tags[inst['inst_id']][inst['tag']]
+        if '.cdf' in fname:
+            temp_inst, _ = clslib.initialize_test_inst_and_date(inst)
+            if temp_inst.pandas_format and temp_inst.name not in skip_cdf_list:
+                instruments['cdf'].append(inst)
 
 
 class TestInstruments(clslib.InstLibTests):