Adding json validation build (#51)

appveyor.yml

@@ -0,0 +1,13 @@
+version: 1.0.3.{build}
+pull_requests:
+  do_not_increment_build_number: true
+branches:
+  only:
+  - dev
+  - master
+  - v2.x
+max_jobs: 1
+image: Visual Studio 2017
+build_script:
+- ps: >-
+    .\build.ps1

build.ps1

@@ -0,0 +1,34 @@
+$ErrorActionPreference = "Stop"
+
+function LogOperationStart($message) {
+    Write-Host $message -NoNewline
+}
+
+function LogSuccess() {
+    Write-Host -ForegroundColor Green "...Done"
+}
+
+function LogErrorAndExit($errorMessage, $exception) {
+    Write-Host -ForegroundColor Red "...Failed" 
+    Write-Host $errorMessage -ForegroundColor Red
+    if ($exception -ne $null) {
+        Write-Host $exception -ForegroundColor Red | format-list -force
+    }    
+    Exit
+}
+
+Function validateFeedJson()
+{
+    try {
+        $file = Get-Content ".\cli-feed-v3.json" -Raw
+        $jsonObj = ConvertFrom-Json $file
+    } catch  {
+        LogErrorAndExit "The feed content is not valid JSON"  $_.Exception
+    }
+}
+
+# start tests
+
+LogOperationStart "Checking if the feed content is valid json"
+validateFeedJson
+LogSuccess