Added dockerfile

Dockerfile

@@ -0,0 +1,13 @@
+FROM golang:stretch AS builder
+
+WORKDIR /go/src/app
+COPY . .
+RUN go get -d -v
+RUN go build -o app .
+
+FROM keybaseio/client:latest
+
+WORKDIR /home/keybase
+COPY --from=builder /go/src/app/app .
+ENV KEYBASE_SERVICE=1
+CMD ["./app"]