v0.7.0

Added

• BlendMode::Lab, optional feature, can be enabled using features = ["lab"] in Cargo.toml
• GradientBuilder new method css() for parsing css gradient format

Changed

• f64 -> f32.
• GimpGradient is now a optional feature, can be enabled using features = ["ggr"] in Cargo.toml
• Preset gradients move to submodule preset.
• In previous version Gradient is a struct holding LinearGradient, BasisGradient, etc in a Box.
  Now Gradient is a trait. LinearGradient, BasisGradient, etc is now exposed directy,
  and they are implementing Gradient trait.
• CustomGradient renamed to GradientBuilder
• CustomGradientError renamed to GradientBuilderError

Removed

• BlendMode::Hsv

Fixed

• Error parsing GIMP gradient with UTF-8 BOM.