Add kotlin plugin and update dependencies

Author: skydoves

app/build.gradle

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
 apply from: "$rootDir/dependencies.gradle"
 
 android {

app/src/main/res/values/colors.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-  <color name="colorPrimary">#F50057</color>
+  <color name="colorPrimary">#FFF50057</color>
   <color name="colorPrimaryDark">#C51162</color>
   <color name="colorAccent">#3d95c9</color>
   <color name="background">#2B292B</color>

build.gradle

@@ -16,18 +16,22 @@ buildscript {
     apply from: "$rootDir/dependencies.gradle"
     repositories {
         jcenter()
+        mavenCentral()
         google()
     }
     dependencies {
         classpath "com.android.tools.build:gradle:$versions.gradleBuildTool"
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$versions.kotlin"
         classpath "com.diffplug.spotless:spotless-plugin-gradle:$versions.spotlessGradle"
-        classpath "com.jfrog.bintray.gradle:gradle-bintray-plugin:$versions.bintrayPlugin"
+        classpath "com.vanniktech:gradle-maven-publish-plugin:$versions.mavenPublish"
+        classpath "org.jetbrains.dokka:dokka-gradle-plugin:$versions.dokkaGradle"
     }
 }
 
 allprojects {
     repositories {
         jcenter()
+        mavenCentral()
         google()
     }
 }

colorpickerview/build.gradle

@@ -13,8 +13,8 @@
 // limitations under the License.
 
 apply plugin: 'com.android.library'
+apply plugin: 'kotlin-android'
 apply from: "$rootDir/dependencies.gradle"
-apply from: "$rootDir/publish.gradle"
 
 android {
   compileSdkVersion versions.compileSdk

dependencies.gradle

@@ -18,10 +18,13 @@ ext.versions = [
     versionoCode     : 26,
     versionName      : '2.2.2',
 
-    gradleBuildTool  : '4.1.0',
-    spotlessGradle   : '5.8.0',
-    bintrayPlugin    : '1.8.5',
+    gradleBuildTool  : '4.1.1',
+    spotlessGradle   : '5.9.0',
+    ktlintGradle     : '0.40.0',
+    dokkaGradle      : '1.4.20',
+    mavenPublish     : '0.13.0',
 
+    kotlin           : '1.4.20',
     androidxAppcompat: '1.2.0',
 
     // for demo