Downgrade docker for now

.dockerignore

@@ -5,5 +5,7 @@ docker-compose.yml
 .vs
 .vscode
 legacy
+packages
+build
 */bin
 */obj

build/Dockerfile

@@ -1,4 +1,4 @@
-FROM microsoft/dotnet:2.1-sdk AS build
+FROM microsoft/dotnet:2.0-sdk AS build
 WORKDIR /src
 
 COPY tgstation-server.sln ./
@@ -36,7 +36,7 @@ RUN dotnet test -c Release
 FROM build AS publish
 RUN dotnet publish -c Release -o /app
 
-FROM microsoft/dotnet:2.1-runtime
+FROM microsoft/dotnet:2.0-runtime
 EXPOSE 80
 
 WORKDIR /app

src/Tgstation.Server.Host/Controllers/ApiController.cs

@@ -7,7 +7,6 @@ using System;
 using System.Collections.Generic;
 using System.Globalization;
 using System.IdentityModel.Tokens.Jwt;
-using System.Linq;
 using System.Security.Claims;
 using System.Threading.Tasks;
 using Tgstation.Server.Api;