add drone ci

.drone.yml

@@ -0,0 +1,37 @@
+workspace:
+  base: /go
+  path: src/github.com/go-xorm/builder
+
+clone:
+  git:
+    image: plugins/git:next
+    depth: 50
+    tags: true
+
+matrix:
+  GO_VERSION:
+    - 1.8
+    - 1.9
+    - 1.10
+    - 1.11
+
+pipeline:
+  test:
+    image: golang:${GO_VERSION}
+    commands:
+      - go get -u github.com/golang/lint/golint
+      - go get -u github.com/stretchr/testify/assert
+      - go get -u github.com/go-xorm/sqlfiddle
+      - golint ./...
+      - go test -v -race -coverprofile=coverage.txt -covermode=atomic
+    when:
+      event: [ push, tag, pull_request ]
+
+codecov:
+    image: robertstettner/drone-codecov
+    group: build
+    secrets: [ codecov_token ]
+    files:
+      - coverage.txt
+    when:
+      event: [ push, pull_request ]

README.md

@@ -1,6 +1,6 @@
 # SQL builder
 
-[![CircleCI](https://circleci.com/gh/go-xorm/builder/tree/master.svg?style=svg)](https://circleci.com/gh/go-xorm/builder/tree/master)  [![codecov](https://codecov.io/gh/go-xorm/builder/branch/master/graph/badge.svg)](https://codecov.io/gh/go-xorm/builder)
+[![GitCI.cn](https://gitci.cn/api/badges/go-xorm/builder/status.svg)](https://gitci.cn/go-xorm/builder)  [![codecov](https://codecov.io/gh/go-xorm/builder/branch/master/graph/badge.svg)](https://codecov.io/gh/go-xorm/builder)
 [![](https://goreportcard.com/badge/github.com/go-xorm/builder)](https://goreportcard.com/report/github.com/go-xorm/builder)
 
 Package builder is a lightweight and fast SQL builder for Go and XORM.