Moving Dockerfile, multistage build

Dockerfile

@@ -0,0 +1,9 @@
+FROM golang:alpine AS build
+
+WORKDIR /root/
+COPY * /root/
+RUN go build -o /root/matrix-handler cmd/svr/main.go
+
+FROM scratch
+COPY --from=build /root/matrix-handler /bin/matrix-handler
+ENTRYPOINT ["/bin/matrix-handler"]