Add Travis continuous integration service for the Github project

Reference links: https://www.jianshu.com/p/3b8d86f25ee2
http://www.ruanyifeng.com/blog/2017/12/travis_ci_tutorial.html

 

Following are the modifications

1. Add Pages and the Github ( https://docs.travis-ci.com/user/deployment/pages/ ) Search gh-pages to get the link

deploy:
  provider: pages
  skip_cleanup: true
  github_token: $GITHUB_TOKEN  # Set in the settings page of your repository, as a secure variable
  keep_history: true
  on:
    branch: master

Here's $ GITHUB_TOKEN in the personal token GitHub configuration (settings token link: https://help.github.com/en/articles/creating-a-personal-access-token-for-the-command-line )

Since this is a private token, the document mentioned in one of two ways can be used to configure the environment variables obtained by travis