fix(cmd): fixes the command resolver
fix(cmd): fixes the command resolver

this fixes the way how to find the proper command. First it looks whether a subfolder named like the command is existing, then if a file named like the command and eventually exists with an error message

Fixes issue https://github.com/aurelia/cli/issues/46

damianof/cli,ghidello/cli,mpean/aurelia-cli,aurelia/cli,hitesh97/cli,santosh-suresh/cli,talves/aurelia-cli,santosh-suresh/cli,DrSammyD/cli,mbroadst/cli,mbroadst/cli,ghidello/cli,hitesh97/cli,ahmedshuhel/cli,DrSammyD/cli,mpean/aurelia-cli,sqli-nantes/aurelia-cli,talves/aurelia-cli,ahmedshuhel/cli,aurelia/cli,damianof/cli,Mordred/cli,zewa666/cli,zewa666/cli,jdanyow/cli,Mordred/cli,zewa666/cli,DrSammyD/cli,jdanyow/cli,zewa666/cli,sqli-nantes/aurelia-cli,ghidello/cli