Add basic license integ test

Original commit: elastic/x-pack-elasticsearch@248f2a745d

plugin/pom.xml

@@ -16,6 +16,8 @@
          -->
         <keys.path>${basedir}/src/test/resources</keys.path>
         <license.basedir combine.self="override">${project.parent.basedir}</license.basedir>
+        <tests.rest.suite>license</tests.rest.suite>
+        <tests.rest.load_packaged>false</tests.rest.load_packaged>
     </properties>
 
     <dependencies>

plugin/rest-api-spec/api/licenses.json

@@ -0,0 +1,19 @@
+{
+  "licenses": {
+    "documentation": "https://www.elastic.co/guide/en/shield/current/license-management.html",
+    "methods": ["GET"],
+    "url": {
+      "path": "/_licenses",
+      "paths": ["/_licenses"],
+      "parts" : {
+      },
+      "params": {
+        "local": {
+          "type" : "boolean",
+          "description" : "Return local information, do not retrieve the state from master node (default: false)"
+        }
+      }
+    },
+    "body": null
+  }
+}

plugin/rest-api-spec/test/license/10_basic.yaml

@@ -0,0 +1,4 @@
+---
+"licenses endpoint exists":
+    - do:         {licenses: {}}
+    - match:      {licenses: []}

plugin/src/test/java/org/elasticsearch/license/plugin/rest/LicensesRestIT.java

@@ -0,0 +1,27 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+package org.elasticsearch.license.plugin.rest;
+
+
+import com.carrotsearch.randomizedtesting.annotations.Name;
+import com.carrotsearch.randomizedtesting.annotations.ParametersFactory;
+import org.elasticsearch.test.rest.ElasticsearchRestTestCase;
+import org.elasticsearch.test.rest.RestTestCandidate;
+import org.elasticsearch.test.rest.parser.RestTestParseException;
+
+import java.io.IOException;
+
+public class LicensesRestIT extends ElasticsearchRestTestCase {
+
+    public LicensesRestIT(@Name("yaml") RestTestCandidate testCandidate) {
+        super(testCandidate);
+    }
+
+    @ParametersFactory
+    public static Iterable<Object[]> parameters() throws IOException, RestTestParseException {
+        return ElasticsearchRestTestCase.createParameters(0, 1);
+    }
+}