v3.0.0

Improvements

• Add TravisCI/Coveralls integration using SmalltalkCI
• Include Buoy as dependency
• CssColorUnit can now be converted to Javascript (thanks @serpi90)

Backward incompatible changes

• Removed CssInstanceCreationFailed in favour of InstanceCreationFailed already provided by Buoy
• Removed CssPercentage in favour of Percentage provided by Buoy