add travis. (#4)

Signed-off-by: Bo-Yi Wu <appleboy.tw@gmail.com>

.travis.yml

@@ -0,0 +1,24 @@
+language: go
+sudo: false
+go:
+  - 1.6.x
+  - 1.7.x
+  - 1.8.x
+  - master
+
+git:
+  depth: 3
+
+install:
+  - go get -u github.com/campoy/embedmd
+
+script:
+  -  embedmd -d README.md
+
+notifications:
+  webhooks:
+    urls:
+      - https://webhooks.gitter.im/e/7f95bf605c4d356372f4
+    on_success: change  # options: [always|never|change] default: always
+    on_failure: always  # options: [always|never|change] default: always
+    on_start: false     # default: false

README.md

@@ -1,5 +1,6 @@
 # sentry
 
+[![Build Status](https://travis-ci.org/gin-contrib/sentry.svg?branch=master)](https://travis-ci.org/gin-contrib/sentry)
 [![Go Report Card](https://goreportcard.com/badge/github.com/gin-contrib/sentry)](https://goreportcard.com/report/github.com/gin-contrib/sentry)
 [![GoDoc](https://godoc.org/github.com/gin-contrib/sentry?status.svg)](https://godoc.org/github.com/gin-contrib/sentry)
 [![Join the chat at https://gitter.im/gin-gonic/gin](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/gin-gonic/gin)
@@ -10,6 +11,7 @@ Middleware to integrate with [sentry](https://getsentry.com/) crash reporting.
 
 See the [example](example/main.go)
 
+[embedmd]:# (example/main.go go)
 ```go
 package main