[upgrade-py-node-build-versions] Now building with xenial and sudo so the 3.7 builds will complete, since that's the only way to use 3.7 on Travis-CI right now.

.travis.yml

@@ -1,6 +1,8 @@
 language: python
 python: 3.7
 env: TRAVIS_NODE_VERSION=10
+dist: xenial
+sudo: true
 branches:
   only:
     - master