Set an end-date for python 3.5 support

Author: Byron

doc/source/changes.rst

@@ -2,6 +2,11 @@
 Changelog
 =========
 
+3.1.15 (UNRELEASED)
+======
+
+* add deprectation warning for python 3.5
+
 3.1.14
 ======
 

git/cmd.py

@@ -908,8 +908,8 @@ def transform_kwargs(self, split_single_char_options=True, **kwargs):
         # order.
         if sys.version_info[:2] < (3, 6):
             kwargs = OrderedDict(sorted(kwargs.items(), key=lambda x: x[0]))
-            warnings.warn("Python 3.5 support is deprecated. It does not preserve the order\n" +
-                          "for key-word arguments. Thus they will be sorted!!")
+            warnings.warn("Python 3.5 support is deprecated and will be removed 2021-09-05.\n" +
+                          "It does not preserve the order for key-word arguments and enforce lexical sorting instead.")
         args = []
         for k, v in kwargs.items():
             if isinstance(v, (list, tuple)):