updated IOT hub Eventhub nuget ref.

Author: Ajit Navasare (MINDTREE LIMITED)

src/IotHub/IotHub.Test/IotHub.Test.csproj

@@ -11,7 +11,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.Azure.Management.EventHub" Version="2.3.0" />
+    <PackageReference Include="Microsoft.Azure.Management.EventHub" Version="2.4.0" />
     <PackageReference Include="Microsoft.Azure.Management.IotHub" Version="2.8.0-preview" />
   </ItemGroup>