Merge pull request #211 from zhy1985555/master

update travis config

Author: zhy1985555

.travis.yml

@@ -5,16 +5,16 @@ python:
 - '3.5'
 - '3.6'
 - '3.7'
-- '3.10'
+- '3.9'
 install:
 - pip install requests
 - pip install six
 - pip install nose
 - pip install pycodestyle
+- pip install importlib_metadata
 - pip install dicttoxml
 - pip install crcmod
 - pip install pycryptodome
-- pip install importlib_metadata
 notifications:
   email:
     recipients: