Drop mvc dependency down to 2.0

Author: kevinkuszyk

samples/FluentAssertions.AspNetCore.Mvc.Sample/FluentAssertions.AspNetCore.Mvc.Sample.csproj

@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.6" />
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
   </ItemGroup>
 
 </Project>

src/FluentAssertions.AspNetCore.Mvc/FluentAssertions.AspNetCore.Mvc.csproj

@@ -26,7 +26,7 @@
 
   <ItemGroup>
     <PackageReference Include="FluentAssertions" Version="5.0.0" />
-    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.0.3" />
+    <PackageReference Include="Microsoft.AspNetCore.Mvc" Version="2.0.0" />
   </ItemGroup>
 
 </Project>