OkHttp的使用过程中出错：Picasso detected an unsupported OkHttp on the classpath.

在写依赖库的时候要写三个：
compile 'com.squareup.okhttp:okhttp:2.4.0'
compile 'com.squareup.okhttp:okhttp-urlconnection:2.2.0'
compile 'com.squareup.picasso:picasso:2.4.0'