chore: use correct cli arg

achingbrain · achingbrain · commit 5ffbe21c1441 · 2021-03-02T15:58:45.000Z
diff --git a/.travis.yml b/.travis.yml
@@ -40,7 +40,7 @@ jobs:
       name: firefox
       addons:
         firefox: latest
-      script: npx aegir test -t browser -- --browsers firefox
+      script: npx aegir test -t browser -- --browser firefox
 
     - stage: test
       name: electron-main
