4.21.0 - Some improvements

Some improvements

• Fix a bug with getting the latest milestone driver version
• Fix a bug with "invalid session id"
• Add "replica" to --env=ENV options
• Improve error-handling with UC Mode
• Update the algorithm that decides if UC Mode calls reconnect()
• Make improvements to "driver.uc_click(selector)" (UC Mode only)
• Add a customizable "timeout" arg to "highlight()" methods
• Refresh Python dependencies
• Update the documentation
• Update example tests

What's Changed

• Some improvements by @mdmintz in #2257

Full Changelog: v4.20.9...v4.21.0