ci: Travis: run py37-lsof-xdist

Author: blueyed

.travis.yml

@@ -66,7 +66,7 @@ jobs:
 
     - stage: baseline
       env: TOXENV=py27-pexpect,py27-trial,py27-numpy
-    - env: TOXENV=py37-xdist
+    - env: TOXENV=py37-lsof-xdist
     - env: TOXENV=linting,docs,doctesting
       python: '3.7'