ENH: allow kwargs for read_xls

src/caosadvancedtools/table_importer.py

@@ -144,7 +144,7 @@ class XLSImporter(object):
         self.unique_keys = [] if unique_keys is None else unique_keys
         self.converters = converters
 
-    def read_xls(self, filename):
+    def read_xls(self, filename, **kwargs):
         """
         converts an xls file into a Pandas DataFrame.
 
@@ -169,7 +169,7 @@ class XLSImporter(object):
                 "All but the first are being ignored.".format(filename))
 
         try:
-            df = xls_file.parse(converters=self.converters)
+            df = xls_file.parse(converters=self.converters, **kwargs)
         except Exception as e:
             logger.warning(
                 "Cannot parse {}.".format(filename),