title: Amazon Cognito Auth library causes gradle IOException (Duplicate zip entry)
body: <p>Ever since I updated CognitoAuth to v2.6.13 I have had compile issues with gradle. This ONLY happens with release builds.</p>
  
  <p>cognito library</p>
  
  <pre><code>'com.amazonaws:aws-android-sdk-cognitoauth:2.6.13'
  </code></pre>
  
  <p>The error I receive is the following:</p>
  
  <blockquote>
    <p>Warning:Exception while processing task java.io.IOException: Can't
    write
    [C:\JAVASDK\AndroidStudio\AS_Workspace\example.android\app\build\intermediates\transforms\proguard\tech\release\0.jar]
    (Can't read
    [C:\Users\jeff.gradle\caches\transforms-1\files-1.1\aws-android-sdk-cognitoauth-2.6.13.aar\cc705c348189e750e6a133ffd448563c\jars\classes.jar(;;;;;;**.class)]
    (Duplicate zip entry
    [classes.jar:com/amazonaws/cognito/clientcontext/datacollection/BuildDataCollector.class]))</p>
  </blockquote>
  
  <p>From research, it seems I need to exclude something but I do not know what. What am I missing? And is this more of a proguard issue, since this only fails with release builds?</p>
  
  <p>EDIT</p>
  
  <pre><code>apply plugin: 'com.android.library'
  
  // top-level build file to help synchronize library versions
  ext {
      supportLib = "25.3.1"
      googleLib = "11.6.0"
      amazonLib = "2.6.3"
  }
  
  allprojects {
      repositories {
          maven { url 'https://maven.fabric.io/public' }
          maven { url 'https://zendesk.jfrog.io/zendesk/repo' }
          maven { url 'https://jitpack.io' }
          jcenter()
          google()
      }
  }
  
  android {
      compileSdkVersion 26
      buildToolsVersion '26.0.2'
      // construct version name
      def versionMajor = 2
      def versionMinor = 0
      def versionPatch = 0
      defaultConfig {
          minSdkVersion 16
          targetSdkVersion 26
          versionName "${versionMajor}.${versionMinor}.${versionPatch}"
          versionCode 1
      }
      buildTypes {
          debug {
              buildConfigField "String", "FEATURES", "\"Device Utilities, "Google Service APIs, TextToSpeech\""
              manifestPlaceholders = [build_version: "${versionMajor}.${versionMinor}.${versionPatch}"]
              // debuggable
              debuggable true
          }
          stage {
              buildConfigField "String", "FEATURES", "\"Device Utilities, "Google Service APIs, TextToSpeech\""
              manifestPlaceholders = [build_version: "${versionMajor}.${versionMinor}.${versionPatch}"]
              // debuggable
              debuggable true
          }
          release {
              buildConfigField "String", "FEATURES", "\"Device Utilities, "Google Service APIs, TextToSpeech\""
              manifestPlaceholders = [build_version: "${versionMajor}.${versionMinor}.${versionPatch}"]
              minifyEnabled true
              proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
          }
      }
  
      dependencies {
          api files('libs/volley.jar')
          // okhttp for requests
          // gson library
          api 'com.google.code.gson:gson:2.8.0'
          // mixpanel
          api 'com.mixpanel.android:mixpanel-android:5.2.1'
          // google play services
          api "com.google.android.gms:play-services:${googleLib}"
          // android support libraries
          api 'com.android.support:multidex:1.0.2'
          api "com.android.support:support-annotations:${supportLib}"
          //noinspection GradleCompatible
          api "com.android.support:cardview-v7:${supportLib}"
          //noinspection GradleCompatible
          api "com.android.support:appcompat-v7:${supportLib}"
          //noinspection GradleCompatible
          api "com.android.support:recyclerview-v7:${supportLib}"
          //noinspection GradleCompatible
          api "com.android.support:design:${supportLib}"
          //noinspection GradleCompatible
          api "com.android.support:appcompat-v7:${supportLib}"
          //noinspection GradleCompatible
          api "com.android.support:customtabs:${supportLib}"
          // amazon libraries
          api "com.amazonaws:aws-android-sdk-cognito:${amazonLib}"
          api "com.amazonaws:aws-android-sdk-cognitoidentityprovider:${amazonLib}"
          api 'com.amazonaws:aws-android-sdk-cognitoauth:2.6.13'
          // unit testing dependencies
          testApi 'junit:junit:4.12'
          // set this dependency if you want to use Mockito
          testApi 'org.mockito:mockito-core:2.7.22'
          // set this dependency if you want to use Hamcrest matching
          androidTestApi 'org.hamcrest:hamcrest-library:1.3'
      }
  
  }
  </code></pre>