Reorganize CI matrix

.travis.yml

@@ -1,40 +1,22 @@
 language: python
-python:
-  - 3.6
-  - 3.6-dev
-sudo: false
-dist: trusty
+dist: xenial
 
 matrix:
   include:
-    # As of 2018-07-05, Travis's 3.7 and 3.8 builds only work if you
-    # use dist: xenial AND sudo: required
-    # See: https://github.com/python-trio/trio/pull/556#issuecomment-402879391
+    - python: 3.5
+    - python: 3.6
     - python: 3.7
-      dist: xenial
-      sudo: required
     - python: 3.7-dev
-      dist: xenial
-      sudo: required
+    - python: 3.8
     - python: 3.8-dev
-      dist: xenial
-      sudo: required
-    # - os: linux
-    #   language: generic
-    #   env: USE_PYPY_RELEASE_VERSION=5.9-beta
-    # Uncomment if you want to test on pypy nightly
-    # - os: linux
-    #   language: generic
-    #   env: USE_PYPY_NIGHTLY=1
+    - python: nightly
     - os: osx
       language: generic
       env: MACPYTHON=3.6.3
     - python: 3.6
       env: CHECK_DOCS=1
     - python: 3.6
       env: CHECK_FORMATTING=1
-  allow_failures:
-    - python: 3.8-dev
 
 script:
   - ci/travis.sh

newsfragments/66.feature.rst

@@ -0,0 +1,2 @@
+Substantially reorganize monkeypatching for asyncio event loop and event loop policy
+accessors, fixing support for Python 3.8.