Dredd exited without an interesting error message

because we were using '\r' in our blueprint file. This now prints: 

info: Beginning Dredd testing...
the use of carriage return(s) '\r' in source data isn't currently supported, please contact makers
undefined

the undefined is because this error doesn't have a stack.
Merge pull request #37 from albertjan/patch-1

Dredd exited without an interesting error message