use Gradle v4.10, android tools v3.1.4, bintray plugin v1.8.4

.travis.yml

@@ -1,5 +1,5 @@
 language: java
-sudo: false
+sudo: true
 dist: precise
 
 branches:

build.gradle

@@ -1,10 +1,11 @@
 buildscript {
     repositories {
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.1.0'
+        classpath 'com.android.tools.build:gradle:3.1.4'
-        classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.5'
+        classpath 'com.jfrog.bintray.gradle:gradle-bintray-plugin:1.8.4'
     }
 }
 
@@ -115,10 +116,6 @@ task mergedSource(type: Copy){
 
 }
 
-task wrapper(type: Wrapper, description: 'Creates and deploys the Gradle wrapper to the current directory.') {
-    gradleVersion = '4.1'
-}
-
 ext {
     ndkCommandPath  = ""
     ndkExists       = false

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,5 @@
-#Sun Sep 17 22:55:30 EDT 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10-bin.zip