Added testing for nested translate commands
Added a hexagon command to the DSL

Started moving DSL commands into a dedicated module
Fixed the max, min, and minmax properties for Sketches with groups and transformations
Changed push to return the Sketch instead of the pushed element

This makes it similar to the behavior of Array#push, which returns self as opposed to the pushed element.
Added first and last accessors
The size property should return a Size, not a Point
Added testing for Sketch::DSL
Added rudimentary support for horizontal and vertical layout groups

This still needs a lot of work, but it's good enough for now.
Added a spacing option to the layout command
Added an align option to the layout command
Added Layout examples to README
Require geometry ~> 6.1
Version 0.2