Ability to specify PSES branch and fork in CI build (#2604)

* Specify PSES Branch

* added fork info

* add log

* typo

Co-authored-by: Robert Holt <rjmholt_msft@outlook.com>

Author: TylerLeonhardt

.vsts-ci/templates/ci-general.yml

@@ -3,8 +3,14 @@ steps:
   - pwsh: Write-Host "##vso[build.updatebuildnumber]$env:BUILD_SOURCEBRANCHNAME-$env:BUILD_SOURCEVERSION-$((get-date).ToString("yyyyMMddhhmmss"))"
     displayName: Set Build Name for Non-PR
     condition: ne(variables['Build.Reason'], 'PullRequest')
+  - task: PowerShell@2
+    displayName: 'Set environment variables for VSTS (Phase 1)'
+    inputs:
+      targetType: filePath
+      filePath: ./tools/releaseBuild/setVstsVariables.ps1
   - pwsh: |
-      git clone https://github.com/PowerShell/PowerShellEditorServices.git ../PowerShellEditorServices
+      Write-Host "Cloning '$env:PSES_BRANCH' branch from '$env:PSES_FORK/PowerShellEditorServices'"
+      git clone --single-branch --branch $env:PSES_BRANCH https://github.com/$env:PSES_FORK/PowerShellEditorServices.git ../PowerShellEditorServices
       Install-Module InvokeBuild -Scope CurrentUser -Force
       Install-Module PlatyPS -Scope CurrentUser -Force
   # Build

tools/releaseBuild/setVstsVariables.ps1

@@ -1,5 +1,6 @@
 $vstsVariables = @{
     PSES_BRANCH = 'master'
+    PSES_FORK = 'PowerShell'
 }
 
 # Use VSTS's API to set an env vars