Upgrade gradle and Kotlin version (#8)

* Upgrade Android Build Gradle Plugin and Kotlin version

* Upgrade gradle wrapper version

build.gradle

@@ -1,12 +1,13 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.1.2-5'
+    ext.kotlin_version = '1.1.60'
     repositories {
         jcenter()
+        google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.2'
+        classpath 'com.android.tools.build:gradle:3.0.1'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
 
         // NOTE: Do not place your application dependencies here; they belong
@@ -17,6 +18,7 @@ buildscript {
 allprojects {
     repositories {
         jcenter()
+        google()
     }
 }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,5 @@
-#Tue Jun 20 13:39:06 CEST 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-3.4.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.3-bin.zip

gradlew

@@ -33,11 +33,11 @@ DEFAULT_JVM_OPTS=""
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD="maximum"
 
-warn ( ) {
+warn () {
     echo "$*"
 }
 
-die ( ) {
+die () {
     echo
     echo "$*"
     echo
@@ -155,7 +155,7 @@ if $cygwin ; then
 fi
 
 # Escape application args
-save ( ) {
+save () {
     for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
     echo " "
 }