Don't look in gatsby/node_modules
Don't look in gatsby/node_modules

I thought this was necessary for npm link development but perhaps not? I
dunno... npm link is weird. Regardless, this breaks installing the 1.0
branch normally as then `node_modules/gatsby/node_modules` doesn't exist
which causes the webpack validation to fail.

ChristopherBiscardi/gatsby,danielfarrell/gatsby,0x80/gatsby,gatsbyjs/gatsby,mingaldrichgan/gatsby,gatsbyjs/gatsby,chiedo/gatsby,gatsbyjs/gatsby,fk/gatsby,ChristopherBiscardi/gatsby,mingaldrichgan/gatsby,ChristopherBiscardi/gatsby,fabrictech/gatsby,0x80/gatsby,Khaledgarbaya/gatsby,okcoker/gatsby,0x80/gatsby,Khaledgarbaya/gatsby,gatsbyjs/gatsby,mickeyreiss/gatsby,mingaldrichgan/gatsby,okcoker/gatsby,fabrictech/gatsby,gatsbyjs/gatsby,fabrictech/gatsby,fk/gatsby,danielfarrell/gatsby,danielfarrell/gatsby,okcoker/gatsby,mickeyreiss/gatsby,chiedo/gatsby,ChristopherBiscardi/gatsby,Khaledgarbaya/gatsby,fk/gatsby,mickeyreiss/gatsby,chiedo/gatsby,gatsbyjs/gatsby