Update readme example to pin to major version

Author: ericsciple

README.md

@@ -41,10 +41,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@master
+        uses: actions/checkout@v2
       - name: Create Release
         id: create_release
-        uses: actions/create-release@latest
+        uses: actions/create-release@v1
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }} # This token is provided by Actions, you do not need to create your own token
         with: