Add "mqttwarn-contrib" package to the list of "extra" dependencies

By doing this, the package will also be installed into the
"mqttwarn-full" Docker image, thus making operating mqttwarn with
custom extensions on Docker-compatible environments way easier.

Author: amotl

CHANGES.rst

@@ -11,6 +11,7 @@ in progress
 - Add launch configuration for VSCode. Thanks, David!
 - Use STDERR as default log target
 - Stop including the "tests" folder into the sdist package
+- Add "mqttwarn-contrib" package to the list of "extra" dependencies
 
 
 2021-06-18 0.25.0

setup.py

@@ -113,6 +113,11 @@
     'slixmpp': [
         'slixmpp>=1.5.2',
     ],
+    # More notification plugins from the community.
+    # https://github.com/daq-tools/mqttwarn-contrib
+    'contrib': [
+        'mqttwarn-contrib',
+    ],
 }