Revert EntityFrameworkCore to 2.0

Author: jwmsft

LunchScheduler.Repository/LunchScheduler.Repository.csproj

@@ -17,9 +17,9 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="3.0.0-preview3.19153.1" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="3.0.0-preview3.19153.1" />
-    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="3.0.0-preview3.19153.1">
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="2.0.0" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Tools" Version="2.0.0">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
     </PackageReference>