raise error if no combo of files detected

Author: zm711

neo/rawio/spikeglxrawio.py

@@ -298,6 +298,9 @@ def scan_files(dirname):
                 info["bin_file"] = str(bin_filename)
                 info_list.append(info)
 
+    if len(info_list) == 0:
+        raise FileNotFoundError(f'No appropriate combination of .meta and .bin files were detected in {print(dirname)}')
+
     # the segment index will depend on both 'gate_num' and 'trigger_num'
     # so we order by 'gate_num' then 'trigger_num'
     # None is before any int