Cancel support Python earlie 3.5

.travis.yml

@@ -11,7 +11,8 @@ services:
   - docker
 
 python:
-  - "2.7"
+  - "3.5"
+  - "3.6"
   - "3.7"
   - "3.8"
 

setup.py

@@ -51,7 +51,7 @@ setup(
     name='webdavclient3',
     version=version,
     packages=find_packages(),
-    requires=['python (>= 2.7.6)'],
+    requires=['python (>= 3.3.0)'],
     install_requires=['requests', 'lxml', 'python-dateutil'],
     scripts=['wdc'],
     test_suite='tests',
@@ -73,7 +73,8 @@ setup(
         'Operating System :: MacOS',
         'Operating System :: Microsoft',
         'Operating System :: Unix',
-        'Programming Language :: Python :: 2.7',
+        'Programming Language :: Python :: 3.5',
+        'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
         'Topic :: Internet',