Update "checkout" action to v2 (#1422)

bsideup · web-flow · commit 3870a256cb16 · 2020-06-24T10:05:42.000+02:00
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
@@ -16,7 +16,7 @@ jobs:
           - { name: "Docker 18.06.3", dockerVersion: "18.06.3~ce~3-0~ubuntu" }
 
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: Set up JDK 8
         uses: actions/setup-java@v1
         with:
