Actions : Update to checkout@v2

This is said to fix "reference is not a tree" errors when retrying a workflow:

actions/checkout#23 (comment)

Author: jpsim

.github/workflows/cmake.yml

@@ -30,7 +30,7 @@ jobs:
     env:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode_version }}.app
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - run: brew install cmake ninja
       - run: swift -version
       - run: cmake -B build -G Ninja -S . -DCMAKE_BUILD_TYPE=Release

.github/workflows/jazzy.yml

@@ -27,7 +27,7 @@ jobs:
     container:
       image: norionomura/jazzy:0.13.2_swift-5.2.1
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - run: bundle install --path vendor/bundle
       - run: swift build
       - name: Generate documentation json

.github/workflows/nightly.yml

@@ -29,6 +29,6 @@ jobs:
     container:
       image: norionomura/swift:nightly
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - run: YAMS_DEFAULT_ENCODING=UTF16 swift test --parallel
       - run: YAMS_DEFAULT_ENCODING=UTF8 swift test --parallel

.github/workflows/pod_lib_lint.yml

@@ -24,6 +24,6 @@ jobs:
     env:
       DEVELOPER_DIR: /Applications/Xcode_11.4.app
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - run: bundle install --path vendor/bundle
       - run: bundle exec pod lib lint --verbose

.github/workflows/swiftlint.yml

@@ -11,6 +11,6 @@ jobs:
   SwiftLint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: GitHub Action for SwiftLint
         uses: norio-nomura/[email protected]

.github/workflows/swiftlint_analyze.yml

@@ -25,7 +25,7 @@ jobs:
     env:
       DEVELOPER_DIR: /Applications/Xcode_11.4.app
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - name: Generate xcodebuild.log
         run: xcodebuild -scheme Yams -project Yams.xcodeproj clean build-for-testing > xcodebuild.log
         shell: bash

.github/workflows/swiftpm.yml

@@ -30,7 +30,7 @@ jobs:
     env:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode_version }}.app
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - run: swift -version
       - run: YAMS_DEFAULT_ENCODING=UTF16 swift test --parallel
       - run: YAMS_DEFAULT_ENCODING=UTF8 swift test --parallel
@@ -43,6 +43,6 @@ jobs:
     container:
       image: swift:${{ matrix.tag }}
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - run: YAMS_DEFAULT_ENCODING=UTF16 swift test --parallel
       - run: YAMS_DEFAULT_ENCODING=UTF8 swift test --parallel

.github/workflows/xcodebuild.yml

@@ -41,7 +41,7 @@ jobs:
     env:
       DEVELOPER_DIR: /Applications/Xcode_${{ matrix.xcode.version }}.app
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v2
       - run: xcodebuild -version
       - name: macOS with UTF16
         if: always()