Update build.ps1

The -Contains operator doesn't do substring comparisons.

> -Contains
>Description: Containment operator. Tells whether a collection of reference values includes a single test value.

Should be using -Match operator instead.

build.ps1

@@ -30,7 +30,7 @@ function CalculateVersion() {
         Exit 1
     }
 
-    if ($semVersion -contains "-") {
+    if ($semVersion -match "-") {
         return "$semVersion-$BuildNumber" #prerelease
     } else {
         return "$semVersion" #release
@@ -127,4 +127,4 @@ foreach ($project in $projectsToBuild) {
     Write-Host "Done." -ForegroundColor "Green"
     Write-Host ""
 }
-Write-Host "Build Complete." -ForegroundColor "Green"
+Write-Host "Build Complete." -ForegroundColor "Green"
\ No newline at end of file