[HUDI-1985] favicon plus misc site fixes

[vingov]

Tips

• Thank you very much for contributing to Apache Hudi.
• Please review https://hudi.apache.org/contributing.html before opening a pull request.

What is the purpose of the pull request

• Fixed favicon on the hudi.apache.org site.
• Move the Our Vision Link to the top of the about footer menu.
• Removed the last updated author and time for all the pages since it's showing my name for all the pages which are not correct plus removed the unnecessary CSS.
• Fixed the Travis build to rebase before the merge.

Brief change log

• Fixed a bunch of minor issues on the hudi asf site.

Verify this pull request

(Please pick either of the following options)

This change added tests and can be verified as follows:

Run these commands to test the site locally at http://localhost:3000/:
Note: ensure you have npm installed

./website/scripts/build-site.sh
cd website
npm run serve

Manually verified the website re-design changes by running the site locally.

Committer checklist

• Has a corresponding JIRA in PR title & commit

• Commit message is descriptive of the change

• CI is green

• Necessary doc changes done or have another open PR

• For large changes, please consider breaking it into sub-tasks under an umbrella JIRA.

[danny0405]

This also need fix: => Spark Guide

[vinothchandar]

Missed your comment by a minute or so :(

[vingov]

@danny0405 - I will review and fix all the titles and send the PR soon, I preserved most of the original titles but that doesn't make sense with this new navigation links.