README: new screenshot, add contributing section

* some related changes in Testing.md

fixes #13963

README.md

@@ -31,6 +31,21 @@ the [REST API](doc/70-REST-API.md) and last but not least our [FAQ](doc/80-FAQ.m
 
 A complete list of all our documentation can be found in the [doc](doc/) directory.
 
+Contributing
+------------
+
+Icinga Director is an Open Source project and lives from your contributions. No
+matter whether these are feature requests, issues, translations, documentation
+or code.
+
+* Please check whether a related issue alredy exists on our [Issue Tracker](https://dev.icinga.com/projects/icingaweb2-module-director/issues)
+* Make sure your code conforms to the [PSR-2: Coding Style Guide](http://www.php-fig.org/psr/psr-2/)
+* [Unit-Tests](doc/93-Testing.md) would be great
+* Send a [Pull Request](https://github.com/Icinga/icingaweb2-module-director/pulls)
+ (it will automatically be tested on Travis-CI)
+* We try hard to keep our master always green: [![Build Status](https://travis-ci.org/Icinga/icingaweb2-module-director.svg?branch=master)](https://travis-ci.org/Icinga/icingaweb2-module-director)
+
+
 Addons
 ------
 

doc/93-Testing.md

@@ -1,10 +1,9 @@
-Running Unit-Tests for the Director
-===================================
+<a id="Testing"></a>Running Unit-Tests for the Director
+=======================================================
 
 There are basically multiple ways of running our Unit-Tests. All of them
 are explained here.
 
-
 Let others do the job
 ---------------------
 
@@ -13,6 +12,26 @@ there is probably already someone running them from time to time. So, just
 lean back with full trust in our development toolchain and spend your time
 elsewhere ;-) Cheers!
 
+### Tests on Travis-CI
+
+When pushing to [GitHub](https://github.com/Icinga/icingaweb2-module-director/)
+or sending pull requests, Unit-Tests are automatically triggered on
+[Travis-CI](https://travis-ci.org/Icinga/icingaweb2-module-director):
+
+[![Build Status](https://travis-ci.org/Icinga/icingaweb2-module-director.svg?branch=master)](https://travis-ci.org/Icinga/icingaweb2-module-director)
+
+We run our tests against MySQL and PostgreSQL, with PHP versions ranging from
+5.3 to 7.1, including nightly builds.
+
+### Tests for supported Platforms
+
+As far as we know, Director is currently mostly used on CentOS (or RHEL)
+versions 6 and 7, Debian Stable (Jessie) and Ubuntu LTS (Xenial). So we are
+running our tests on our own platforms for exactly those systems. All of them
+with PostgreSQL, MySQL (or MariaDB).
+
+This way we reach the mostly used Database and PHP versions:
+
 ![Test result](screenshot/director/93_testing/931_director_testing_duration.png)