Explicitly set the jruby-complete up for the compile configuration

Fixes #12

src/main/groovy/com/github/jrubygradle/jar/JRubyJarPlugin.groovy

@@ -21,6 +21,7 @@ class JRubyJarPlugin implements Plugin<Project> {
 
         project.apply plugin : 'com.github.jruby-gradle.base'
         project.apply plugin : 'java-base'
+        project.configurations.maybeCreate('compile')
         project.configurations.maybeCreate('jrubyEmbeds')
         project.configurations.maybeCreate('jrubyJar')
 
@@ -41,6 +42,14 @@ class JRubyJarPlugin implements Plugin<Project> {
                 stubTask
         )
 
+        project.repositories {
+            jcenter()
+        }
+
+        project.dependencies {
+            compile group: 'org.jruby', name: 'jruby-complete', version: project.jruby.defaultVersion
+        }
+
         project.configure(stubTask) {
             group JRubyPlugin.TASK_GROUP_NAME
             description 'Generates a JRuby Java bootstrap class'

src/test/groovy/com/github/jrubygradle/jar/JRubyJarPluginSpec.groovy

@@ -1,6 +1,7 @@
 package com.github.jrubygradle.jar
 
 import org.gradle.api.Task
+import org.gradle.api.artifacts.Dependency
 import org.gradle.api.file.FileCollection
 import org.gradle.api.tasks.bundling.Jar
 import org.gradle.api.tasks.compile.JavaCompile
@@ -96,6 +97,9 @@ class JRubyJarPluginSpec extends Specification {
 
         then: "Then the attribute should be set to the default in the manifest"
             jarTask.manifest.attributes.'Main-Class' == JRubyJarConfigurator.DEFAULT_BOOTSTRAP_CLASS
+
+        and: "Then jruby-complete should be added as a dependency"
+            project.configurations.getByName('compile').dependencies.matching { Dependency d -> d.name == 'jruby-complete' }
     }
 
     def "Adding all defaults"() {