add Dockerfile

Dockerfile

@@ -0,0 +1,10 @@
+FROM golang:alpine AS builder
+WORKDIR /build
+ADD go.mod .
+COPY . .
+RUN go build 
+FROM alpine
+WORKDIR /build
+COPY --from=builder /build/mini-beieli-lorahandler /build/mini-beieli-lorahandler
+CMD ["./mini-beieli-lorahandler"]
+EXPOSE 8080