Added missing header

tools/maven-plugin/src/main/java/com/kumuluz/ee/openapi/mp/mavenplugin/GenerateMojo.java

@@ -1,3 +1,23 @@
+/*
+ *  Copyright (c) 2014-2017 Kumuluz and/or its affiliates
+ *  and other contributors as indicated by the @author tags and
+ *  the contributor list.
+ *
+ *  Licensed under the MIT License (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  https://opensource.org/licenses/MIT
+ *
+ *  The software is provided "AS IS", WITHOUT WARRANTY OF ANY KIND, express or
+ *  implied, including but not limited to the warranties of merchantability,
+ *  fitness for a particular purpose and noninfringement. in no event shall the
+ *  authors or copyright holders be liable for any claim, damages or other
+ *  liability, whether in an action of contract, tort or otherwise, arising from,
+ *  out of or in connection with the software or the use or other dealings in the
+ *  software. See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
 package com.kumuluz.ee.openapi.mp.mavenplugin;
 
 import io.smallrye.openapi.mavenplugin.GenerateSchemaMojo;
@@ -22,8 +42,10 @@
 import static org.twdata.maven.mojoexecutor.MojoExecutor.*;
 
 /**
+ * Saves OpenAPI schema to file by delegating execution to SmallRye plugin.
+ *
  * @author benjamink, Sunesis ltd.
- * @since 1.0.0
+ * @since 1.3.0
  */
 @Mojo(
         name = "generate",