Chore: Tweak Travis config
Chore: Tweak Travis config

- Add libconf to fix Cypress after Ubuntu upgrade (https://github.com/cypress-io/cypress/issues/4069)
- Update npm version to 6.9

styleguidist/react-styleguidist,styleguidist/react-styleguidist,styleguidist/react-styleguidist,sapegin/react-styleguidist,sapegin/react-styleguidist