Fix enforcement to check for non-existent package versions. Fixes #44.
Fix enforcement to check for non-existent package versions. Fixes #44.

nazriel/dub,Abscissa/dub-data-mod,schuetzm/dub,rjframe/dub,y12uc231/dub,Flamaros/dub,p0nce/dub,D-Programming-Language/dub,dreamsxin/dub,alexeibs/dub,grogancolin/dub,MartinNowak/dub,Geod24/dub,jeanbaptistelab/dub,gedaiu/dub,xentec/dub,Abscissa/dub,jelmansouri/dub