(GH-2153) (build) downgrade to Microsoft.Extension.* 3.0.0

Author: arturcic

src/Directory.Build.props

@@ -22,7 +22,7 @@
         <PackageVersion_JetBrainsAnnotations>2019.1.3</PackageVersion_JetBrainsAnnotations>
         <PackageVersion_YamlDotNet>8.1.0</PackageVersion_YamlDotNet>
         <PackageVersion_NewtonsoftJson>12.0.3</PackageVersion_NewtonsoftJson>
-        <PackageVersion_MicrosoftExtensions>3.1.2</PackageVersion_MicrosoftExtensions>
+        <PackageVersion_MicrosoftExtensions>3.0.0</PackageVersion_MicrosoftExtensions>
 
         <PackageVersion_MicrosoftTestSdk>16.5.0</PackageVersion_MicrosoftTestSdk>
         <PackageVersion_NSubstitute>4.2.1</PackageVersion_NSubstitute>