fix ci error

Author: jnhyperion

.travis.yml

@@ -1,8 +1,12 @@
 language: python
-python:
-  - "3.8"
-  - "3.9"
-  - "3.10"
+matrix:
+  include:
+    - python: 3.8
+      env: TOXENV=py38
+    - python: 3.9
+      env: TOXENV=py39
+    - python: 3.10
+      env: TOXENV=py310
 install: "pip install -r requirements-dev.txt"
 script:
   - invoke style-check