Update selenium to 3.7.0

[pyup-bot]

There's a new version of selenium available.
You are currently using 3.6.0. I have updated it to 3.7.0

These links might come in handy: PyPI | Changelog | Repo

Changelog

3.7.0

• need to pass applicable environment variables to tox
• Fix active_element for w3c drivers (3979)
• add support for minimize command
• add support for fullscreen command
• window rect commands should fail on firefox and remote (legacy)
• Fix python backward compatibility for window commands (4937)
• Update docstrings to specify the type of path needed to install firefox addons. (4881)
• Update python chromeOptions key for capabilities (4622)
• Fix python pause action implementation (4795)

Got merge conflicts? Close this PR and delete the branch. I'll create a new PR for you.

Happy merging! 🤖