Migrate docker configuration to .NET 5.0

Author: liborpansky

Dockerfile

@@ -1,8 +1,8 @@
-FROM mcr.microsoft.com/dotnet/core/aspnet:3.1-buster-slim AS base
+FROM mcr.microsoft.com/dotnet/aspnet:5.0-buster-slim AS base
 WORKDIR /app
 EXPOSE 80
 
-FROM mcr.microsoft.com/dotnet/core/sdk:3.1 AS build
+FROM mcr.microsoft.com/dotnet/sdk:5.0 AS build
 WORKDIR /src
 COPY ["./AspNetCoreVueStarter.csproj", "app/"]
 RUN dotnet restore "app/AspNetCoreVueStarter.csproj"