title: Gradle error: "Attribute "rippleColor" has already been defined" in android studio
body: <p>So I was trying out the material design support library and when I added the dependency, compiled, and I got this error.
  I looked at similar problems and tried their solutions but it would not get fixed so I hope you can help me.</p>
  
  <p>Here's my logcat:</p>
  
  <pre><code>C:\Users\Jan\AndroidStudioProjects\SwagCalculator3\app\build\intermediates\exploded-aar\com.android.support\appcompat-v7\22.2.0\res\values\values.xml
  Error:(1) Attribute "rippleColor" has already been defined
  </code></pre>
  
  <p>and here is my build.gradle:  </p>
  
  <pre><code>apply plugin: 'com.android.application'
  
  android {
  compileSdkVersion 22
  buildToolsVersion "22.0.1"
  
  defaultConfig {
      applicationId "com.raptor.swagcalculator.swagcalculator"
      minSdkVersion 21
      targetSdkVersion 22
  
  }
  buildTypes {
      release {
          minifyEnabled false
          proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
      }
  }
  }
  
  dependencies {
  compile fileTree(dir: 'libs', include: ['*.jar'])
  compile 'com.android.support:design:22.2.0'
  compile 'com.android.support:appcompat-v7:22.2.0'
  compile 'com.android.support:support-v4:22.2.0'
  compile 'com.android.support:cardview-v7:22.2.0'
  }
  </code></pre>