Requirements fix

Update colorpalette deps (#7)

dev-master of heyday/colorpalette is now only core ^4.0 compatible, this pins the core 3.x version of colorpalette to the 3.x compatible version of brand module.

Silverstripe 4 support

Merge pull request #3 from adrexia/feature/silverstripe4

FIX: Silverstripe 4 support

Initial release

Working with silverstripe 3