update gitignore
fix indentation
Design class
Allow multiple designs per section
Allow extra context to be passed in Design instance
fix in add_child_ad_hoc
refactor generation of ExpreimentSection.children
add option to append children to either end of section
better attribute name context_managers
Design.ivs is a dict
wait to parse designs
fix levels_and_designs syntax
DesignTree objects
sections use DesignTrees
Experiment takes DesignTree
add warning