Merge branch 'master' into suggester_java9plus_fix

Author: tarzanek

.mvn/wrapper/maven-wrapper.properties

@@ -1 +1 @@
-distributionUrl=https://repo1.maven.org/maven2/org/apache/maven/apache-maven/3.3.3/apache-maven-3.3.3-bin.zip
+distributionUrl=https://repo1.maven.org/maven2/org/apache/maven/apache-maven/3.5.4/apache-maven-3.5.4-bin.zip

CONTRIBUTING.md

@@ -9,5 +9,8 @@ When submitting a new Issue for what seems is a bug, please note the version you
 
 Make sure to add a comment line line to the changeset saying which Issue it is is fixing, e.g. 'fixes #XYZ' so that the issue can be automatically closed when the associated pull request is merged.
 
+Each pull request should be accompanied by a comment explaining how the change was tested, unless unit tests are provided/updated.
+Please make every effort to make most of your changes covered by tests.
+
 For a pull request to be merged, we need the contributor to sign Oracle Contributor Agreement first.
 See http://www.oracle.com/technetwork/community/oca-486395.html for details.

README.md

@@ -7,6 +7,8 @@ Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
 [![wercker status](https://app.wercker.com/status/e2a879f4677e679c0bbf8fa82bcc0dba/s/master "wercker status")](https://app.wercker.com/project/byKey/e2a879f4677e679c0bbf8fa82bcc0dba)
 [![Coverage status](https://coveralls.io/repos/oracle/opengrok/badge.svg?branch=master)](https://coveralls.io/r/oracle/opengrok?branch=master)
 [![SonarQube status](https://sonarcloud.io/api/project_badges/measure?project=org.opengrok%3Aopengrok-top&metric=alert_status)](https://sonarcloud.io/dashboard?id=org.opengrok%3Aopengrok-top)
+[![AppVeyor status](https://ci.appveyor.com/api/projects/status/8oqlk5yx2c5fnwqw/branch/master?svg=true)](https://ci.appveyor.com/project/vladak/opengrok-b5hnp/branch/master)
+[![License](https://img.shields.io/badge/License-CDDL%201.0-blue.svg)](https://opensource.org/licenses/CDDL-1.0)
 
 1. [Introduction](#1-introduction)
 2. [OpenGrok setup](#2-opengrok-install-and-setup)