ci(travis): update yarn

Author: Spaier

.travis.yml

@@ -10,7 +10,7 @@ addons:
 node_js:
 - '10.11.0'
 before_install:
-  - curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version 1.9.4
+  - curl -o- -L https://yarnpkg.com/install.sh | bash -s -- --version 1.10.1
   - export PATH="$HOME/.yarn/bin:$PATH"
 install:
   - yarn