update build tool

build.gradle

@@ -18,7 +18,7 @@ buildscript {
         // Check that you have the Google Services Gradle plugin v4.3.2 or later
         // (if not, add it).
         classpath 'com.google.gms:google-services:4.3.3'
-        classpath 'com.google.firebase:firebase-crashlytics-gradle:2.0.0-beta01'
+        classpath 'com.google.firebase:firebase-crashlytics-gradle:2.0.0-beta02'
 
         // protobuf plugin - docs here https://github.com/google/protobuf-gradle-plugin
         classpath 'com.google.protobuf:protobuf-gradle-plugin:0.8.11'