Could not find method android() for arguments

I’ve been trying to import a project to Android Studio and this is where I am stuck, there is a similar question on Stack Overflow but it did not provide a solution to my particular error.

This is my error log:

C:\<some location>\build.gradle

Error:(24, 1) A problem occurred evaluating root project '<project name>'.
> Could not find method android() for arguments [build_4fli1jm76ubcnxesnhqnhie47$_run_closure3@6e71db85] on root project '<project name>'.
Information:BUILD FAILED

The Gradle sync messages are:

Error:(24, 0) Gradle DSL method not found: ‘android()’ Possible causes:The project ‘PoojaPeople’ may be using a version of Gradle that does not contain the method. Gradle settingsThe build file may be missing a Gradle plugin. Apply Gradle plugin

I’m not too sure where exactly this method android() is located. If it is the one located in Application’s build.gradle file, I still don’t exactly know where to go from here. Any help is appreciated.

My build.gradle is

buildscript {
    repositories {
        maven { url "http://dl.bintray.com/populov/maven" }
        mavenCentral()
    }
     dependencies {
        classpath 'com.android.tools.build:gradle:2.1.0'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}
allprojects {
    repositories {
        maven { url "http://dl.bintray.com/populov/maven" }
        mavenCentral()

    }
}
task clean(type: Delete) {
    delete rootProject.buildDir
}

android {
    compileSdkVersion 17
    buildToolsVersion '23.0.0'
}
dependencies {
    compile files('app/libs/junit-4.12-JavaDoc.jar')
}
apply plugin: 'maven'