Update README.md

[luixxiul]

Make it clear how to run webdriver tests locally

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

Test Plan:

[cezaraugusto]

++