Use voice android sdk 4.2.0. Updated compiled, target SDK version and…

… gradle version (#295)

app/build.gradle

@@ -1,8 +1,7 @@
 apply plugin: 'com.android.application'
 
 android {
-    compileSdkVersion 27
-    buildToolsVersion "27.0.3"
+    compileSdkVersion 28
 
     compileOptions {
         sourceCompatibility 1.8
@@ -46,9 +45,9 @@ android {
 dependencies {
     testImplementation 'junit:junit:4.12'
 
-    implementation 'com.twilio:voice-android:4.1.0'
-    implementation 'com.android.support:design:27.0.2'
-    implementation 'com.android.support:appcompat-v7:27.0.2'
+    implementation 'com.twilio:voice-android:4.2.0'
+    implementation 'com.android.support:design:28.0.0'
+    implementation 'com.android.support:appcompat-v7:28.0.0'
     implementation 'com.squareup.retrofit:retrofit:1.9.0'
     implementation 'com.koushikdutta.ion:ion:2.1.8'
     implementation 'com.google.firebase:firebase-messaging:11.0.4'

build.gradle

@@ -10,7 +10,7 @@ buildscript {
         google()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.1.3'
+        classpath 'com.android.tools.build:gradle:3.4.2'
         classpath 'com.google.gms:google-services:3.2.0'
 
         // NOTE: Do not place your application dependencies here; they belong

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Fri Sep 28 15:41:43 PDT 2018
+#Mon Jul 29 13:28:27 PDT 2019
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-4.4-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.1.1-all.zip