[Error] Could not find com.android.support:support-v4:23.4.0.

## 현상

A problem occurred configuring project ':SlidingMenu'.
> Could not resolve all dependencies for configuration ':SlidingMenu:_debugPublishCopy'.
   > Could not find com.android.support:support-v4:23.4.0.
     Required by:
         project :SlidingMenu

Possible solution:
 - Declare repository providing the artifact, see the documentation at https://docs.gradle.org/current/userguide/declaring_repositories.html

## 해결방안

build.gradle (Project : App Name)에서 아래 코드로 업데이트

allprojects {
    repositories {
        jcenter()
        maven {
            url "https://maven.google.com"
        }
    }
}