Updates nuget packages.

Author: jcasale

src/PSSerilog/PSSerilog.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="Microsoft.PowerShell.5.1.ReferenceAssemblies" Version="1.0.0" PrivateAssets="All" />
-    <PackageReference Include="Serilog" Version="2.12.0" />
+    <PackageReference Include="Serilog" Version="3.0.0" />
     <PackageReference Include="Serilog.Enrichers.Environment" Version="2.2.0" />
     <PackageReference Include="Serilog.Enrichers.GlobalLogContext" Version="3.0.0" />
     <PackageReference Include="Serilog.Enrichers.Process" Version="2.0.2" />