my application include QR Scanner and Generator but when i add 'com.google.android.gms:play-services-vision:9.4.0' library it conflect with 'com.google.firebase:firebase-database:11.0.4' library
plus it shows me an error .. Error:Execution failed for task ':app:processDebugGoogleServices'.
Please fix the version conflict either by updating the version of the google-services plugin (information about the latest version is available at https://bintray.com/android/android-tools/com.google.gms.google-services/) or updating the version of com.google.android.gms to 9.8.0.