feat: git action branch setting

.github/workflows/CICD.yml

@@ -5,9 +5,9 @@ name: CI/CD using github actions & docker
 # main브랜치에 pull request가 발생 되었을 때 실행
 on:
   pull_request:
-    branches: [ "main" ]
+    branches: [ "master" ]
   push:
-    branches: [ "main" ]
+    branches: [ "master" ]
 
 permissions:
   contents: read