add circle CI config

.circleci/config.yml

@@ -0,0 +1,15 @@
+# Golang CircleCI 2.0 configuration file
+#
+# Check https://circleci.com/docs/2.0/language-go/ for more details
+version: 2
+jobs:
+  build:
+    docker:
+      # specify the version
+      - image: circleci/golang:1.11
+    working_directory: /go/src/github.com/goproxyio/goproxy/
+    steps:
+      - checkout
+
+      # specify any bash command here prefixed with `run: `
+      - run: bash circle-test.sh

circle-test.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+export GO111MODULE=on
+go mod download
+go mod verify
+go test -timeout 60s -v ./...
+# build
+go build -v -mod readonly