title: How to properly configure Kotlin plugin for Gradle?
body: <p>I'm trying to build a basic Gradle project. My <code>build.gradle</code> file is below. I keep getting the below error. I don't get it because you can find the plugin here... where I think I'm directing to: <a href="https://mvnrepository.com/artifact/org.jetbrains.kotlin/kotlin-gradle-plugin" rel="noreferrer">https://mvnrepository.com/artifact/org.jetbrains.kotlin/kotlin-gradle-plugin</a></p>
  
  <p>Update: same thing happens to the spring-boot plugin if I comment out the Kotlin line. It's not just specific to the Kotlin plugin.</p>
  
  <p>The error:</p>
  
  <pre><code>Error:(21, 0) Plugin [id: 'kotlin', version: '1.1.1'] was not found in any of the following sources: 
  - Gradle Core Plugins (not a core plugin, please see https://docs.gradle.org/3.3/userguide/standard_plugins.html for available core plugins) 
  - Gradle Central Plugin Repository (no 'kotlin' plugin available - see https://plugins.gradle.org for available plugins)
  </code></pre>
  
  <p>Build.gradle:</p>
  
  <pre><code>buildscript {
  
  
      ext.kotlin_version = '1.1.1'
  
      repositories {
          mavenCentral()
      }
      dependencies {
          classpath("org.springframework.boot:spring-boot-gradle-plugin:1.2.6.RELEASE")
          classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
      }
  
  
  }
  
  plugins {
      id 'java'
      id 'kotlin' version "1.1.1"
      id 'spring-boot'
  }
  
  
  
  group 'si.dime.kotlin.tutorials.rest'
  version '1.0-SNAPSHOT'
  
  sourceCompatibility = 1.8
  
  repositories {
      mavenCentral()
  }
  
  sourceSets {
      main.java.srcDirs += 'src/main/kotlin'
  }
  
  dependencies {
      compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
      compile("org.springframework.boot:spring-boot-starter-web:1.3.3.RELEASE")
  }
  </code></pre>