Android Travis CI Error: failed to find target with hash string 'android-23' in: /usr/local/android-sdk

I am trying to learn how to use Travis CI in Android , but when I push my code to the Github, Travis CI gives me an error : failed to find target with hash string 'android-23' in: /usr/local/android-sdk,

my .travis.yml file is :

language: android
android:
  components:
    - build-tools-23.0.0
    - android-L
    - sys-img-x86-android-tv-l
    - add-on
    - extra
script: ./gradlew assembleDebug

And my build.gradle file is :

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.0"

defaultConfig {
    applicationId "xhome.uestcfei.com.loadingpoppointdemo"
    minSdkVersion 15
    targetSdkVersion 23
    versionCode 1
    versionName "1.0"
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:23.0.0'
    compile 'com.android.support:design:23.0.0'
    compile project(':loadingpoppoint')
}

I am new to Travis CI ,I search for solutions by Google ,there are solutions for this error ,but worked only for local compilation rather than Travis CI . Is anybody can help me out?

Really Thanks a lot !