Removes double require in spec_helper.
Removes double require in spec_helper.

See https://github.com/ruby-grape/grape/issues/1155.

peterwillcn/grape,xurde/grape,hnq90/grape,samotarnik/grape,pvijayror/grape,fangzhu19880123/grape,tylerdooling/grape,dblock/grape,shunyam/grape,hobofan/grape,marshall-lee/grape,rnubel/grape,niedhui/grape,gencer/grape,ferdinandrosario/grape,klaustopher/grape,cutalion/grape,thogg4/grape,suan/grape,reynardmh/grape,dslh/grape,namusyaka/grape,ruby-grape/grape,jlfaber/grape,intridea/grape