Update checkout action version (#659)

* Update checkout action version

Author: mnaumanali94

.github/workflows/spectral.yml

@@ -7,7 +7,7 @@ jobs:
     name: Spectral checks
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
       - name: Test this action against an incorrect file.
         id: expect-failure
         continue-on-error: true

README.md

@@ -20,7 +20,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       # Check out the repository
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v3
 
       # Run Spectral
       - uses: stoplightio/spectral-action@latest