Update Travis configuration to use new main branch name.

Quintin Willison · Quintin Willison · commit e1b1a16e5c48 · 2020-07-08T11:04:46.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -70,5 +70,5 @@ notifications:
 
 branches:
   only:
-  - master
+  - main
   - /^.*-ci$/
