Merge pull request #2334 from mikeller/enable_azure_pr_validation

Enabled pull request validation in azure.

azure-pipelines.yml

@@ -24,12 +24,19 @@ parameters:
     default: false
 
 name: $(Date:yyyyMMdd).$(BuildID)
+
 trigger:
   batch: true
   branches:
     include:
     - master
-pr: none
+
+pr:
+  drafts: false
+  branches:
+    include:
+      - master
+      - "*-maintenance"
 
 stages:
 - stage: Build