Fix path of powershell script

.github/workflows/test.yml

@@ -18,12 +18,12 @@ jobs:
       uses: actions/checkout@v2
       with:
         fetch-depth: 0
-    - name: Perform a Pester test from the command-line
+    - name: File exists
       shell: pwsh
       run: Test-Path $Env:GITHUB_WORKSPACE\test.ps1 | Should -Be $true
     - name: Create msi from PowerShell Script
       run: |
-        ./"$Env:GITHUB_WORKSPACE\test.ps1"
+        ./"$Env:GITHUB_WORKSPACE/test.ps1"
     - name: Upload artifacts
       uses: actions/upload-artifact@v2
       with: