Don't test with editing README (#480)

.github/workflows/test.yml

@@ -3,8 +3,12 @@ name: test
 on:
   push:
     branches: [ "master" ]
+    paths-ignore:
+      - '**/README.md'
   pull_request:
     branches: [ "master" ]
+    paths-ignore:
+      - '**/README.md'
 
 jobs:
   check: