Use checkout v2

.github/workflows/deploy.yml

@@ -9,7 +9,7 @@ jobs:
   create-binaries:
     runs-on: windows-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Install Rust
       uses: actions-rs/toolchain@v1
       with:
@@ -35,7 +35,7 @@ jobs:
       FILENAME: oxipng-windows-sdk
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@master
+    - uses: actions/checkout@v2
     - name: Download the zip
       uses: actions/download-artifact@v1
       with:

.github/workflows/oxipng.yml

@@ -28,7 +28,7 @@ jobs:
           - conf: latest-nightly
             toolchain: nightly
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Install ${{ matrix.toolchain }}
       uses: actions-rs/toolchain@v1
       with:
@@ -82,7 +82,7 @@ jobs:
           - conf: latest-stable
             toolchain: stable
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Install ${{ matrix.toolchain }}
       uses: actions-rs/toolchain@v1
       with: