remove refs to strictHierarchy for #891
remove refs to strictHierarchy for #891

KonstantinShemyak/cytoscape.js,soomin-maeng/cytoscape.js,soomin-maeng/cytoscape.js,KonstantinShemyak/cytoscape.js,rlugojr/cytoscape.js,rlugojr/cytoscape.js