do not add root pkg to ancestors
do not add root pkg to ancestors

The ancestors list is only relevant for detecting pathological cycles in
the dep history.  However, the root package is often NOT actually
require()-able, so is not in the family list, but will (reasonably) be
in the dependency hash of a package being installed.  So, omit it as an
ancestor.

Fixes installing `lru-cache` in development mode.  No non-dev-mode
use-cases have been encountered.

princeofdarkness76/npm,Volune/npm,evocateur/npm,midniteio/npm,ekmartin/npm,princeofdarkness76/npm,rsp/npm,Volune/npm,lxe/npm,ekmartin/npm,segment-boneyard/npm,TimeToogo/npm,DIREKTSPEED-LTD/npm,yodeyer/npm,thomblake/npm,segrey/npm,chadnickbok/npm,yibn2008/npm,xalopp/npm,haggholm/npm,yodeyer/npm,DaveEmmerson/npm,evanlucas/npm,yyx990803/npm,evanlucas/npm,evocateur/npm,segrey/npm,midniteio/npm,cchamberlain/npm-msys2,rsp/npm,haggholm/npm,yodeyer/npm,thomblake/npm,kemitchell/npm,segmentio/npm,Volune/npm,chadnickbok/npm,chadnickbok/npm,segrey/npm,cchamberlain/npm-msys2,cchamberlain/npm,yibn2008/npm,yyx990803/npm,segmentio/npm,kriskowal/npm,DaveEmmerson/npm,kriskowal/npm,DaveEmmerson/npm,segment-boneyard/npm,xalopp/npm,kimshinelove/naver-npm,cchamberlain/npm-msys2,kemitchell/npm,misterbyrne/npm,misterbyrne/npm,yibn2008/npm,DIREKTSPEED-LTD/npm,lxe/npm,cchamberlain/npm,evocateur/npm,thomblake/npm,DIREKTSPEED-LTD/npm,TimeToogo/npm,TimeToogo/npm,yyx990803/npm,xalopp/npm,kemitchell/npm,princeofdarkness76/npm,evanlucas/npm,kimshinelove/naver-npm,rsp/npm,segment-boneyard/npm,misterbyrne/npm,cchamberlain/npm,midniteio/npm,ekmartin/npm,haggholm/npm,kriskowal/npm,lxe/npm,kimshinelove/naver-npm,segmentio/npm