Gradle is failing on syncing my project in the new Android Studio 2.0

Question

I have just upgraded (i.e., installed a full new version) my Android Studio from 1.5 to 2.0. The upgrade seemed to go smoothly, but I am having trouble with my project when

Answer 1

I got same problem when I downloaded "BackboneExampleApp" source code from guithub Click Here For Code. I have done following process by watching settings of my old projects and found these errors. I resolved both errors, run my app and got errors to upgrade project and finally when I updated then no more problems exist. Just see pictures for help.

build.gradle (Project:BackboneExampleApp-master)-->

dependencies {
    classpath 'com.android.tools.build:gradle:2.3.1'
}