avoid using deprecated configurations in the gradle plugin build script

Author: jnizet

spring-boot-project/spring-boot-tools/spring-boot-gradle-plugin/build.gradle

@@ -21,12 +21,12 @@ repositories {
 }
 
 dependencies {
-	compile localGroovy()
-	compile gradleApi()
-	compile fileTree(dir: 'target/dependencies/compile', include: '*.jar')
-	testCompile gradleTestKit()
-	testCompile 'org.apache.commons:commons-compress:1.13'
-	testCompile fileTree(dir: 'target/dependencies/test', include: '*.jar')
+	implementation localGroovy()
+    implementation gradleApi()
+    implementation fileTree(dir: 'target/dependencies/compile', include: '*.jar')
+	testImplementation gradleTestKit()
+    testImplementation 'org.apache.commons:commons-compress:1.13'
+    testImplementation fileTree(dir: 'target/dependencies/test', include: '*.jar')
 }
 
 jar {