Add xenial hacks back

Travis is still retarded

.travis.yml

@@ -11,11 +11,14 @@ jobs:
   include:
     - stage: test
       python: '3.7'
+      dist: xenial
     - python: '3.6'
       env: TOXENV=docs
     - python: '3.7'
+      dist: xenial
       env: TOXENV=djmaster
     - python: '3.7'
+      dist: xenial
       env: TOXENV=lint
 
     - stage: publish