Update old versions in workflow (#68)

Author: webbertakken

.github/workflows/main.yml

@@ -33,7 +33,7 @@ jobs:
     steps:
       # Checkout repository (required to test local actions)
       - name: Checkout repository
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
 
       # Request manual activation file
       - name: Request manual activation file
@@ -44,7 +44,7 @@ jobs:
 
       # Upload artifact (Unity_v20XX.X.XXXX.alf)
       - name: Expose as artifact
-        uses: actions/upload-artifact@v1
+        uses: actions/upload-artifact@v2
         with:
           name: ${{ steps.getManualLicenseFile.outputs.filePath }}
           path: ${{ steps.getManualLicenseFile.outputs.filePath }}