Gradle version updates + add kotlin plugin

Author: dwillmc

app/build.gradle

@@ -1,14 +1,15 @@
 plugins {
     id 'com.android.application'
+    id 'kotlin-android'
 }
 
 android {
-    compileSdkVersion = 27
-    buildToolsVersion = '27.0.3'
+    compileSdkVersion = 28
+    buildToolsVersion = '28.0.0'
     defaultConfig {
         applicationId 'com.jpegkit.app'
         minSdkVersion 15
-        targetSdkVersion 27
+        targetSdkVersion 28
         versionCode 1
         versionName '0.2.0'
         externalNativeBuild {
@@ -31,5 +32,6 @@ repositories {
 
 dependencies {
     implementation project(':jpegkit')
-    implementation 'com.android.support:appcompat-v7:27.1.1'
+    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.2.41'
+    implementation 'com.android.support:appcompat-v7:28.0.0-alpha3'
 }

build.gradle

@@ -4,6 +4,7 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.1.2'
+        classpath 'com.android.tools.build:gradle:3.1.3'
+        classpath 'org.jetbrains.kotlin:kotlin-gradle-plugin:1.2.41'
     }
 }

jpegkit/build.gradle

@@ -1,15 +1,16 @@
 plugins {
     id 'com.android.library'
+    id 'kotlin-android'
     id 'com.jfrog.bintray' version '1.7.3'
     id 'com.github.dcendents.android-maven' version '1.5'
 }
 
 android {
-    compileSdkVersion = 27
-    buildToolsVersion = '27.0.3'
+    compileSdkVersion = 28
+    buildToolsVersion = '28.0.0'
     defaultConfig {
         minSdkVersion 15
-        targetSdkVersion 27
+        targetSdkVersion 28
         externalNativeBuild {
             cmake {
                 cppFlags ''
@@ -29,7 +30,8 @@ repositories {
 }
 
 dependencies {
-    implementation 'com.android.support:exifinterface:27.1.1'
+    implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk7:1.2.41'
+    implementation 'com.android.support:exifinterface:28.0.0-alpha3'
 }
 
 ext.getBintrayUser = { ->