title: spoon gradle : Could not create plugin of type 'AppPlugin'
body: <p>my gradle project was build succeed, but when add spoon ,then i got this error (Could not create plugin of type 'AppPlugin')</p>
  
  <p>my gradle version 1.9</p>
  
  <p>build.gradle :</p>
  
  <pre><code>buildscript {
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath 'com.android.tools.build:gradle:0.7.+'
          classpath 'com.stanfy.spoon:spoon-gradle-plugin:0.9.+'
      }
  }
  apply plugin: 'android'
  apply plugin: 'spoon'
  
  repositories {
      mavenCentral()
  }
  
  android {
      compileSdkVersion 19
      buildToolsVersion "19.0.0"
  
      defaultConfig {
          minSdkVersion 10
          targetSdkVersion 19
      }
  }
  
  dependencies {
      compile 'com.android.support:appcompat-v7:+'
      instrumentTestCompile 'com.jayway.android.robotium:robotium-solo:4.3.1'
      instrumentTestCompile 'com.squareup.spoon:spoon-client:1.0.5'
  }
  </code></pre>