官方描述：
Sometimes you don’t need ajax, or you prefer to use one of the many standalone libraries that focus on ajax requests. And often it is simpler to use a combination of CSS and class manipulation for all your web animations. Along with the regular version of jQuery that includes the ajax and effects modules, we’ve released a “slim” version that excludes these modules. All in all, it excludes ajax, effects, and currently deprecated code. The size of jQuery is very rarely a load performance concern these days, but the slim build is about 6k gzipped bytes smaller than the regular version – 23.6k vs 30k.
介绍：JQuery.slim.js去掉了Ajax部分，体积变小了
使用场景：如果不需要使用JQ的Ajax，或者有更好的Ajax库，则使用JQuery.slim.js非常合适
