Switch from node 10 to 12 at Travis.

Author: mshima

.travis.yml

@@ -1,7 +1,7 @@
 sudo: false
 language: node_js
 node_js:
-  - 10
+  - 14
   - 12
 after_success:
   - npm run coverage
@@ -15,6 +15,6 @@ env:
     - DOCS_DIR: ../yeoman-generator-doc
     - GH_OWNER: yeoman
     - GH_PROJECT_NAME: generator
-    - DEPLOY_ON_NODE_VERSION: 12
+    - DEPLOY_ON_NODE_VERSION: 14
     - secure: >-
         Hv7gACQoYGtesz1NTJYRHjGCimEJEjj4bQP2iTpDUUbfAiYe/4QPemoyDEFjRxbu5m2uoYwMk0AQrW7DnQhNAhl7u24jYnRgQyd/2GOx3xZgjwnao27gsrTHss4IyXEaS2h3kRuIVSD+xibz/lwZm+erHOQ9VOwvCQkOKnILXW8=