[Doppins] Upgrade dependency gulp-sass to 3.1.0

[doppins-bot]

Hi!

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

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

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Upgraded gulp-sass from 2.3.1 to 3.0.0

Changelog:

Version 2.3.2

Fixes

• Prevent options leaking between source files (@xzyfer, #509)

Misc

• Update some npm deps (@xzyfer, #490)

[doppins-bot]

An additional new version was just released of gulp-sass, so we've added an extra commit upgrading your range to 3.1.0.

Hope that's alright! — Doppins