Add specs for DataMapper::Relationship#via
Add specs for DataMapper::Relationship#via

denyago/rom,endash/rom,rom-rb/rom,jeremyf/rom,cored/rom,pdswan/rom,rom-rb/rom,pvcarrera/rom,Snuff/rom,pxlpnk/rom,dekz/rom,rom-rb/rom,vrish88/rom,dcarral/rom,kwando/rom