Add docker & docker-compose file

Resolves #9

Dockerfile

@@ -0,0 +1,11 @@
+FROM golang:1.16-alpine as builder
+
+WORKDIR /app
+
+COPY . .
+
+RUN apk add build-base && cd server && go mod download && go build && chmod 777 server && ls -l
+
+EXPOSE 8080
+
+ENTRYPOINT [ "/app/server/server" ]