Update NuGet packages. Fix warnings.
diff --git a/tests/DotPulsar.IntegrationTests/DotPulsar.IntegrationTests.csproj b/tests/DotPulsar.IntegrationTests/DotPulsar.IntegrationTests.csproj
index 3f569d1..1184fbd 100644
--- a/tests/DotPulsar.IntegrationTests/DotPulsar.IntegrationTests.csproj
+++ b/tests/DotPulsar.IntegrationTests/DotPulsar.IntegrationTests.csproj
@@ -8,13 +8,13 @@
 
     <ItemGroup>
         <PackageReference Include="FluentAssertions" Version="5.10.3" />
-        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.7.1" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.10.0" />
         <PackageReference Include="xunit" Version="2.4.1" />
         <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>
-        <PackageReference Include="coverlet.collector" Version="1.3.0">
+        <PackageReference Include="coverlet.collector" Version="3.0.3">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>
diff --git a/tests/DotPulsar.IntegrationTests/Services/ServiceFactory.cs b/tests/DotPulsar.IntegrationTests/Services/ServiceFactory.cs
index 01b3c1c..dd0187c 100644
--- a/tests/DotPulsar.IntegrationTests/Services/ServiceFactory.cs
+++ b/tests/DotPulsar.IntegrationTests/Services/ServiceFactory.cs
@@ -18,14 +18,14 @@
 
     public static class ServiceFactory
     {
-        private const string PulsarDeploymentType = "PULSAR_DEPLOYMENT_TYPE";
-        private const string ContainerDeployment = "container";
+        private const string _pulsarDeploymentType = "PULSAR_DEPLOYMENT_TYPE";
+        private const string _containerDeployment = "container";
 
         public static IPulsarService CreatePulsarService()
         {
-            var deploymentType = System.Environment.GetEnvironmentVariable(PulsarDeploymentType);
+            var deploymentType = System.Environment.GetEnvironmentVariable(_pulsarDeploymentType);
 
-            if (deploymentType == ContainerDeployment)
+            if (deploymentType == _containerDeployment)
             {
                 return new StandaloneContainerService();
             }