Update Linux container images:

1. runtime 2.1->2.1.3
2. sdk 2.1->2.1.401

src/ApiGateways/ApiGw-Base/Dockerfile

@@ -1,8 +1,8 @@
-FROM microsoft/dotnet:2.1-aspnetcore-runtime AS base
+FROM microsoft/dotnet:2.1.3-aspnetcore-runtime AS base
 WORKDIR /app
 EXPOSE 80
 
-FROM microsoft/dotnet:2.1-sdk AS build
+FROM microsoft/dotnet:2.1.401-sdk AS build
 WORKDIR /src
 COPY src/ApiGateways/ApiGw-Base/OcelotApiGw.csproj src/ApiGateways/ApiGw-Base/
 RUN dotnet restore src/ApiGateways/ApiGw-Base/

src/Services/Basket/Basket.API/Dockerfile

@@ -2,7 +2,7 @@ FROM microsoft/dotnet:2.1-aspnetcore-runtime AS base
 WORKDIR /app
 EXPOSE 80
 
-FROM microsoft/dotnet:2.1-sdk AS build
+FROM microsoft/dotnet:2.1.304-sdk AS build
 WORKDIR /src
 COPY . .
 WORKDIR /src/src/Services/Basket/Basket.API