build\build.ps1: Updated test task to account for the fact that dotnet.exe cannot run multiple projects at a time
build\build.ps1: Updated test task to account for the fact that dotnet.exe cannot run multiple projects at a time

NightOwl888/lucenenet,NightOwl888/lucenenet,NightOwl888/lucenenet,NightOwl888/lucenenet,jeme/lucenenet,apache/lucenenet,sisve/lucenenet,jeme/lucenenet,laimis/lucenenet,jeme/lucenenet,sisve/lucenenet,apache/lucenenet,apache/lucenenet,apache/lucenenet,jeme/lucenenet,laimis/lucenenet