Update project and tests

build.gradle

@@ -2,12 +2,11 @@ buildscript {
     repositories {
         google()
         jcenter()
-        maven { url 'https://maven.fabric.io/public' }
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.6.3'
+        classpath 'com.android.tools.build:gradle:4.0.0'
         classpath 'com.google.gms:google-services:4.3.3'
-        classpath 'io.fabric.tools:gradle:1.28.0'
+        classpath 'com.google.firebase:firebase-crashlytics-gradle:2.1.1'
     }
 }