Merge pull request #39 from Scott-Caldwell/net5-preview4

Update to .NET 5.0 preview 4

Author: Cisien

Dockerfile

@@ -1,11 +1,11 @@
-FROM mcr.microsoft.com/dotnet/core/sdk:5.0 as dotnet-build
+FROM mcr.microsoft.com/dotnet/sdk:5.0 as dotnet-build
 WORKDIR /src
 COPY . .
 RUN dotnet --info
 RUN dotnet restore CSDiscord.sln --configfile .nuget/nuget.config
 RUN dotnet test CSDiscordService.Tests/CSDiscordService.Tests.csproj
 RUN dotnet publish CSDiscordService/CSDiscordService.csproj -o /app
-FROM mcr.microsoft.com/dotnet/core/aspnet:5.0
+FROM mcr.microsoft.com/dotnet/aspnet:5.0
 RUN apt-get update && apt-get install -y ca-certificates
 WORKDIR /app
 COPY --from=dotnet-build /app .