update node version for ci

Author: npalm

.travis.yml

@@ -1,11 +1,11 @@
 language: node_js
 node_js:
-- '10'
+  - "14"
 
 before_script:
-- npm install -g gatsby-cli
+  - npm install -g gatsby-cli
 script:
-- npm run build
+  - npm run build
 deploy:
   provider: pages
   skip-cleanup: true