Add helpers for directory checking
Add helpers for directory checking

hmoco/waterbutler,icereval/waterbutler,TomBaxter/waterbutler,rafaeldelucena/waterbutler,chrisseto/waterbutler,CenterForOpenScience/waterbutler,kwierman/waterbutler,felliott/waterbutler,rdhyee/waterbutler,RCOSDP/waterbutler,cosenal/waterbutler,Johnetordoff/waterbutler,Ghalko/waterbutler