Make Mapper::Builder build mappers in #initialize
Make Mapper::Builder build mappers in #initialize

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