Fix tabular renderer ext matching error

If a file with an extension that had casing that was not all lowercase
was passed to the tabular renderer, it would not match it with the
proper function.

Author: AddisonSchiller

mfr/extensions/tabular/render.py

@@ -63,7 +63,7 @@ def _populate_data(self, fp, ext):
         :param ext: file extension
         :return: tuple of column headers and row data
         """
-        function_preference = settings.LIBS.get(ext)
+        function_preference = settings.LIBS.get(ext.lower())
 
         for function in function_preference:
             try: