[Doppins] Upgrade dependency bootstrap to 4.3.1

[doppins-bot]

Hi!

A new version was just released of bootstrap, so Doppins
has upgraded your project's dependency ranges.

Make sure that it doesn't break anything, and happy merging!

---

Upgraded bootstrap from 4.1.0 to 4.1.1

Changelog:

Version 4.1.1

Our first patch release for Bootstrap 4! Here's a quick rundown of some of the changes:

• Added validation styles for file inputs
• Improved printing of dark tables
• Suppressed that text-hide deprecation notice by default
• Cleaned up some JS globals and improve coverage
• Bumped dependencies, namely Jekyll
• Fixed docs issue with incorrect name for our monospace font utility

Checkout the v4.1.1 ship list](https://github.com/twbs/bootstrap/issues/25971) and [GitHub project (https://github.com/twbs/bootstrap/projects/13) for the full details.

[doppins-bot]

An additional new version was just released of bootstrap, so we've added an
extra commit upgrading your range to 4.1.2.

Hope that's alright!
— Doppins

[doppins-bot]

An additional new version was just released of bootstrap, so we've added an
extra commit upgrading your range to 4.1.3.

Hope that's alright!
— Doppins

[doppins-bot]

An additional new version was just released of bootstrap, so we've added an
extra commit upgrading your range to 4.2.1.

Hope that's alright!
— Doppins

[doppins-bot]

An additional new version was just released of bootstrap, so we've added an
extra commit upgrading your range to 4.3.0.

Hope that's alright!
— Doppins

[doppins-bot]

An additional new version was just released of bootstrap, so we've added an
extra commit upgrading your range to 4.3.1.

Hope that's alright!
— Doppins