[master] Update dependencies from dotnet/arcade (#3469)

* Update dependencies from https://github.com/dotnet/arcade build 20190725.15

- Microsoft.DotNet.Arcade.Sdk - 1.0.0-beta.19375.15

* Update dependencies from https://github.com/dotnet/arcade build 20190726.18

- Microsoft.DotNet.Arcade.Sdk - 1.0.0-beta.19376.18

eng/common/post-build/post-build-utils.ps1

@@ -0,0 +1,90 @@
+# Most of the functions in this file require the variables `MaestroApiEndPoint`, 
+# `MaestroApiVersion` and `MaestroApiAccessToken` to be globally available.
+
+$ErrorActionPreference = "Stop"
+Set-StrictMode -Version 2.0
+
+# `tools.ps1` checks $ci to perform some actions. Since the post-build
+# scripts don't necessarily execute in the same agent that run the
+# build.ps1/sh script this variable isn't automatically set.
+$ci = $true
+. $PSScriptRoot\..\tools.ps1
+
+function Create-MaestroApiRequestHeaders([string]$ContentType = "application/json") {
+  Validate-MaestroVars
+
+  $headers = New-Object 'System.Collections.Generic.Dictionary[[String],[String]]'
+  $headers.Add('Accept', $ContentType)
+  $headers.Add('Authorization',"Bearer $MaestroApiAccessToken")
+  return $headers
+}
+
+function Get-MaestroChannel([int]$ChannelId) {
+  Validate-MaestroVars
+
+  $apiHeaders = Create-MaestroApiRequestHeaders
+  $apiEndpoint = "$MaestroApiEndPoint/api/channels/${ChannelId}?api-version=$MaestroApiVersion"
+  
+  $result = try { Invoke-WebRequest -Method Get -Uri $apiEndpoint -Headers $apiHeaders | ConvertFrom-Json } catch { Write-Host "Error: $_" }
+  return $result
+}
+
+function Get-MaestroBuild([int]$BuildId) {
+  Validate-MaestroVars
+
+  $apiHeaders = Create-MaestroApiRequestHeaders -AuthToken $MaestroApiAccessToken
+  $apiEndpoint = "$MaestroApiEndPoint/api/builds/${BuildId}?api-version=$MaestroApiVersion"
+
+  $result = try { return Invoke-WebRequest -Method Get -Uri $apiEndpoint -Headers $apiHeaders | ConvertFrom-Json } catch { Write-Host "Error: $_" }
+  return $result
+}
+
+function Get-MaestroSubscriptions([string]$SourceRepository, [int]$ChannelId) {
+  Validate-MaestroVars
+
+  $SourceRepository = [System.Web.HttpUtility]::UrlEncode($SourceRepository) 
+  $apiHeaders = Create-MaestroApiRequestHeaders -AuthToken $MaestroApiAccessToken
+  $apiEndpoint = "$MaestroApiEndPoint/api/subscriptions?sourceRepository=$SourceRepository&channelId=$ChannelId&api-version=$MaestroApiVersion"
+
+  $result = try { Invoke-WebRequest -Method Get -Uri $apiEndpoint -Headers $apiHeaders | ConvertFrom-Json } catch { Write-Host "Error: $_" }
+  return $result
+}
+
+function Trigger-Subscription([string]$SubscriptionId) {
+  Validate-MaestroVars
+
+  $apiHeaders = Create-MaestroApiRequestHeaders -AuthToken $MaestroApiAccessToken
+  $apiEndpoint = "$MaestroApiEndPoint/api/subscriptions/$SubscriptionId/trigger?api-version=$MaestroApiVersion"
+  Invoke-WebRequest -Uri $apiEndpoint -Headers $apiHeaders -Method Post | Out-Null
+}
+
+function Assign-BuildToChannel([int]$BuildId, [int]$ChannelId) {
+  Validate-MaestroVars
+
+  $apiHeaders = Create-MaestroApiRequestHeaders -AuthToken $MaestroApiAccessToken
+  $apiEndpoint = "$MaestroApiEndPoint/api/channels/${ChannelId}/builds/${BuildId}?api-version=$MaestroApiVersion"
+  Invoke-WebRequest -Method Post -Uri $apiEndpoint -Headers $apiHeaders | Out-Null
+}
+
+function Validate-MaestroVars {
+  try {
+    Get-Variable MaestroApiEndPoint -Scope Global | Out-Null
+    Get-Variable MaestroApiVersion -Scope Global | Out-Null
+    Get-Variable MaestroApiAccessToken -Scope Global | Out-Null
+
+    if (!($MaestroApiEndPoint -Match "^http[s]?://maestro-(int|prod).westus2.cloudapp.azure.com$")) {
+      Write-PipelineTaskError "MaestroApiEndPoint is not a valid Maestro URL. '$MaestroApiEndPoint'"
+      ExitWithExitCode 1  
+    }
+
+    if (!($MaestroApiVersion -Match "^[0-9]{4}-[0-9]{2}-[0-9]{2}$")) {
+      Write-PipelineTaskError "MaestroApiVersion does not match a version string in the format yyyy-MM-DD. '$MaestroApiVersion'"
+      ExitWithExitCode 1
+    }
+  }
+  catch {
+    Write-PipelineTaskError "Error: Variables `MaestroApiEndPoint`, `MaestroApiVersion` and `MaestroApiAccessToken` are required while using this script."
+    Write-Host $_
+    ExitWithExitCode 1
+  }
+}