Specify target explicitly as workaround for diffplug/spotless#437

Author: nedtwigg

build.gradle

@@ -69,6 +69,7 @@ tasks.eclipse.dependsOn(pluginUnderTestMetadata)
 ////////////
 spotless {
 	java {
+		target 'src/main/java/**/*.java', 'src/test/java/**/*.java'
 		licenseHeaderFile	'gradle/spotless.license.java'		// License header file
 		importOrderFile		'gradle/spotless.importorder'		// An import ordering file, exported from Eclipse
 		eclipse().configFile'gradle/spotless.eclipseformat.xml'	// XML file dumped out by the Eclipse formatter