.travis-ci: Drop (now) unnecessary dependency

Signed-off-by: Niels Thykier <niels@thykier.net>

.travis.yml

@@ -10,7 +10,7 @@ before_install:
 
 install:
     # install build dependencies
-    - sudo apt-get install -qq --no-install-recommends python3 python3-apt python3-yaml python3-coverage python3-nose rsync libclass-accessor-perl python3-amqplib
+    - sudo apt-get install -qq --no-install-recommends python3 python3-apt python3-yaml python3-coverage python3-nose rsync libclass-accessor-perl
 
 script:
     - nosetests3 -v --with-coverage