Remove travis-ci

Author: cnblogs-dudu

.travis.yml

@@ -2,8 +2,6 @@
 
 This is a .NET Core client library for Memcached migrated from [EnyimMemcached](https://github.com/enyim/EnyimMemcached). Available on Nuget https://www.nuget.org/packages/EnyimMemcachedCore
 
-[![Build Status](https://travis-ci.org/cnblogs/EnyimMemcachedCore.svg?branch=dotnetcore)](https://travis-ci.org/cnblogs/EnyimMemcachedCore)
-
 ## Configure
 ### The appsettings.json Without Authentication
 ```json