Revert "Temporarily removed TreatWarningsAsErrors"

This reverts commit c7fb5763af.

samples/MusicStore/MusicStore.csproj

@@ -6,6 +6,7 @@
     <Description>Music store application on ASP.NET Core</Description>
     <TargetFramework>netcoreapp2.0</TargetFramework>
     <DefineConstants>$(DefineConstants);DEMO</DefineConstants>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <RuntimeIdentifiers Condition="'$(MUSICSTORE_ASPNETCORE_STORE_FEED)' == ''">win7-x86;win7-x64;linux-x64;osx-x64</RuntimeIdentifiers>
   </PropertyGroup>
 

test/MusicStore.E2ETests/MusicStore.E2ETests.csproj

@@ -5,6 +5,7 @@
   <PropertyGroup>
     <TargetFramework>netcoreapp2.0</TargetFramework>
     <UserSecretsId>MusicStore.E2ETests</UserSecretsId>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
     <ServerGarbageCollection>true</ServerGarbageCollection>
     <WarningsNotAsErrors>$(WarningsNotAsErrors);xUnit1004</WarningsNotAsErrors>
   </PropertyGroup>