fix yarn version

Matthias Rütten · Matthias Rütten · commit 68d2d5374565 · 2019-11-05T23:04:47.000+01:00
diff --git a/.travis.yml b/.travis.yml
@@ -3,7 +3,7 @@ sudo: false
 language: node_js
 
 before_install:
-  - curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version 1.17.3
+  - curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version 1.19.1
   - export PATH=$HOME/.yarn/bin:$PATH
 
 install:
