Trio 0.17.0 updates

.travis.yml

@@ -1,8 +1,8 @@
 language: python
-python:
-- 3.5
-- 3.6
-- 3.7
+dist: trusty
+matrix:
+  include:
+    - python: 3.6
 services:
 - rabbitmq
 install:
@@ -12,13 +12,6 @@ install:
 - pip freeze
 env:
 - AMQP_VHOST=test PYTEST=py.test
-before_script:
-- sudo rabbitmq-plugins enable rabbitmq_management
-- wget http://guest:guest@localhost:15672/cli/rabbitmqadmin -O rabbitmqadmin
-- chmod +x rabbitmqadmin
-- ./rabbitmqadmin declare user name=guest password=guest tags=administrator
-- ./rabbitmqadmin declare vhost name=test
-- ./rabbitmqadmin declare permission vhost=test user=guest read=".*" write=".*" configure=".*"
 script:
 - make test
 - coverage