Add invalid_{child,parent}_method_name to nodes
Add invalid_{child,parent}_method_name to nodes

Otherwise, instead of an error that can be useful, we just get:
`undefined method invalid_parent_method_name`

Change-Id: Ic6258018c47b3758869985083befc84345e2cc88
Reviewed-on: http://gerrit.causes.com/44134
Tested-by: jenkins <d95b56ce41a2e1ac4cecdd398defd7414407cc08@causes.com>
Reviewed-by: Shane da Silva <67fb7bfe39f841b16a1f86d3928acc568d12c716@brigade.com>

artemartemov/scss-lint-hdm