Added coveralls badge to readme
Added coveralls badge to readme

nismod/smif,willu47/smif,willu47/smif,nismod/smif,tomalrussell/smif,tomalrussell/smif,willu47/smif,nismod/smif,willu47/smif,tomalrussell/smif,nismod/smif,tomalrussell/smif