Update 2.1 test templates to use the 15.7 preview 1 test SDK

Author: Mike Lorbetske

build/DependencyVersions.props

@@ -22,7 +22,7 @@
     <MicrosoftNETSdkWebProjectSystemPackageVersion>$(MicrosoftNETSdkWebPackageVersion)</MicrosoftNETSdkWebProjectSystemPackageVersion>
     <MicrosoftDotNetCommonItemTemplatesPackageVersion>1.0.1-beta3-20180104-1263555</MicrosoftDotNetCommonItemTemplatesPackageVersion>
     <MicrosoftDotNetCommonProjectTemplates20PackageVersion>1.0.1-beta3-20180104-1263555</MicrosoftDotNetCommonProjectTemplates20PackageVersion>
-    <MicrosoftDotNetTestProjectTemplates20PackageVersion>$(MicrosoftDotNetCommonProjectTemplates20PackageVersion)</MicrosoftDotNetTestProjectTemplates20PackageVersion>
+    <MicrosoftDotNetTestProjectTemplates20PackageVersion>1.0.1-beta3-20180227-1423805</MicrosoftDotNetTestProjectTemplates20PackageVersion>
     <MicrosoftTemplateEngineCliPackageVersion>1.0.0-beta3-20171204-315</MicrosoftTemplateEngineCliPackageVersion>
     <MicrosoftTemplateEngineAbstractionsPackageVersion>$(MicrosoftTemplateEngineCliPackageVersion)</MicrosoftTemplateEngineAbstractionsPackageVersion>
     <MicrosoftTemplateEngineCliLocalizationPackageVersion>$(MicrosoftTemplateEngineCliPackageVersion)</MicrosoftTemplateEngineCliLocalizationPackageVersion>