allow usage of pathlib.Path as filepath specifier

icartt/dataset.py

 import datetime
 import sys
+import pathlib
 import collections
 import re
 import warnings
@@ -788,7 +789,7 @@ class Dataset:
 
         # read data if f is not None
         if f is not None:
-            if isinstance(f, str):
+            if isinstance(f, (str, pathlib.Path)):
                 self.inputFhandle = open(f, 'r')
             else:
                 self.inputFhandle = f