Run tests using headless mode in Travis (currently only Nightly) (#111)

.travis.yml

@@ -5,10 +5,10 @@ _aliases:
       packages:
         - jwm
   - &nightly
-    env: FIREFOX=nightly
+    env: FIREFOX=nightly MOZ_HEADLESS=1
     addons:
-      <<: *apt
       firefox: latest-nightly
+    before_script: skip
   - &dev
     env: FIREFOX=dev
     addons:
@@ -71,9 +71,10 @@ jobs:
       <<: *esr
     - stage: deploy
       python: 3.6
+      before_install: skip
+      install: skip
       before_script: skip
       script: skip
-      install: skip
       deploy:
         provider: pypi
         user: davehunt
@@ -89,13 +90,14 @@ cache:
 env:
   global:
     - DISPLAY=:99.0
-install: pip install tox-travis
-before_script:
+before_install:
   - wget -O /tmp/geckodriver.tar.gz https://github.com/mozilla/geckodriver/releases/download/v0.17.0/geckodriver-v0.17.0-linux64.tar.gz
   - mkdir $HOME/geckodriver && tar xvf /tmp/geckodriver.tar.gz -C $HOME/geckodriver
   - export PATH=$HOME/geckodriver:$PATH
   - firefox --version
   - geckodriver --version
+install: pip install tox-travis
+before_script:
   - sh -e /etc/init.d/xvfb start
   - sleep 10
   - jwm &

tox.ini

@@ -3,7 +3,7 @@ envlist = py{27,36}, flake8, docs
 
 [testenv]
 recreate = True
-passenv = DISPLAY TRAVIS TRAVIS_JOB_ID TRAVIS_BRANCH
+passenv = DISPLAY MOZ_HEADLESS TRAVIS TRAVIS_JOB_ID TRAVIS_BRANCH
 deps = -rrequirements/coverage.txt
 commands =
     pytest --driver=Firefox --cov --html=results/{envname}.html {posargs}