build/build.ps1: Updated script to exclude the Lucene.Net.Tests.Cli project when the framework is not .NET Core 2.0
build/build.ps1: Updated script to exclude the Lucene.Net.Tests.Cli project when the framework is not .NET Core 2.0

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