travis: change xvfb syntax

dhilt · dhilt · commit 4611bb2d5552 · 2019-08-16T03:59:58.000+03:00
diff --git a/.travis.yml b/.travis.yml
@@ -15,6 +15,8 @@ addons:
 
 before_script:
 - export DISPLAY=:99.0
+- xvfb
+- sleep 3
 
 script:
 - npm run build
