Travis CI: remove the deprecated `sudo: false`

https://blog.travis-ci.com/2018-11-19-required-linux-infrastructure-migration

diff --git a/.travis.yml b/.travis.yml
index c35705261235ae0d2ce754ed78fd93128d966d22..15c3ce5ec24b15f7e4e3e680855ab724e6f8156f 100644 (file)
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,8 +3,6 @@ notifications:
 
 language: generic
 
-sudo: false
-
 cache:
   directories:
     - $HOME/miniconda3