Create create_grab_instance method in spider base class
Create create_grab_instance method in spider base class

shaunstanislaus/grab,maurobaraldi/grab,subeax/grab,raybuhr/grab,huiyi1990/grab,liorvh/grab,lorien/grab,alihalabyah/grab,pombredanne/grab-1,SpaceAppsXploration/grab,istinspring/grab,giserh/grab,DDShadoww/grab,raybuhr/grab,shaunstanislaus/grab,giserh/grab,maurobaraldi/grab,DDShadoww/grab,alihalabyah/grab,lorien/grab,huiyi1990/grab,SpaceAppsXploration/grab,codevlabs/grab,kevinlondon/grab,subeax/grab,pombredanne/grab-1,istinspring/grab,subeax/grab,kevinlondon/grab,codevlabs/grab,liorvh/grab