Add underscore as a dependency
Replace utils.set_defaults with _.defaults
Replace utils.each_prop with _.each
Actually remove utils.set_defaults
Replace utils.update with _.extend
Replace utils.pop_prop with _.omit
Merge branch 'develop' into feature/issue-71-add-underscore-as-a-dependency
Merge branch 'feature/issue-71-add-underscore-as-a-dependency' into develop