title: Could not find any version that matches com.android.support:appcompat-v7:29.+
body: <p>I'm at the newest level on Android. just boot up a new project and got error on the Gradle Build with Pie ( Android v9.0):</p>
  
  <blockquote>
    <p>Unable to resolve dependency for
    ':app@debugAndroidTest/compileClasspath': Could not find any version
    that matches com.android.support:appcompat-v7:29.+.</p>
  </blockquote>
  
  <p>this is my <code>build.gradle (Module:app)</code>:</p>
  
  <pre><code>
  apply plugin: 'com.android.library'
  
  android {
      compileSdkVersion 29
      defaultConfig {
          minSdkVersion 28
          targetSdkVersion 29
          versionCode 1
          versionName "1.0"
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
      }
      buildTypes {
          release {
              minifyEnabled false
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  }
  
  dependencies {
      implementation fileTree(dir: 'libs', include: ['*.jar'])
      implementation 'com.android.support:appcompat-v7:29.+'
      implementation 'com.android.support.constraint:constraint-layout:1.1.3'
      testImplementation 'junit:junit:4.12'
      androidTestImplementation 'com.android.support.test:runner:1.0.2'
      androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
  }
  </code></pre>
  
  <p>How do I do next?</p>