Fixed setup.py to install requirements the 'right' way.
Fixed setup.py to install requirements the 'right' way.

Closes #19.

metasoarous/csvkit,elcritch/csvkit,snuggles08/csvkit,Jobava/csvkit,jpalvarezf/csvkit,onyxfish/csvkit,wjr1985/csvkit,aequitas/csvkit,archaeogeek/csvkit,KarrieK/csvkit,arowla/csvkit,unpingco/csvkit,themiurgo/csvkit,tlevine/csvkit,bradparks/csvkit__query_join_filter_CSV_cli,wireservice/csvkit,haginara/csvkit,matterker/csvkit,nriyer/csvkit,kyeoh/csvkit,moradology/csvkit,gepuro/csvkit,dannguyen/csvkit,bmispelon/csvkit,doganmeh/csvkit,Tabea-K/csvkit,barentsen/csvkit,reubano/csvkit,cypreess/csvkit