Update to checkout v3

Author: heiskr

.github/workflows/0-start.yml

@@ -36,7 +36,7 @@ jobs:
     steps:
       # We'll need to check out the repository so that we can edit the README
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           fetch-depth: 0 # Let's get all the branches
 

.github/workflows/1-resolve-a-merge-conflict.yml

@@ -35,7 +35,7 @@ jobs:
     steps:
       # We'll need to check out the repository so that we can edit the README
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           fetch-depth: 0 # Let's get all the branches
           ref: my-resume

.github/workflows/2-create-your-own-conflict.yml

@@ -36,7 +36,7 @@ jobs:
     steps:
       # We'll need to check out the repository so that we can edit the README
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           fetch-depth: 0 # Let's get all the branches
           ref: my-resume

.github/workflows/3-merge-your-pull-request.yml

@@ -34,7 +34,7 @@ jobs:
     steps:
       # We'll need to check out the repository so that we can edit the README
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v3
         with:
           fetch-depth: 0 # Let's get all the branches