add nonroot user creation

Author: relent0r

CoreWebApiTest/Dockerfile

@@ -1,5 +1,8 @@
 # Build runtime image
 FROM microsoft/aspnetcore:2.0
+ENV ASPNETCORE_URLS=http://+:8080
+RUN useradd --create-home -s /bin/bash svcwebuser
 WORKDIR /app
-COPY publish/ .
+USER svcwebuser
+COPY publish/* ./
 ENTRYPOINT ["dotnet", "CoreWebApiTest.dll"]