treat notfound as an error and fail
yellow -> red
add default 'test' and 'validate' scripts only if they are defined because notfound is now an error
add a warning if default is not found
produce "failed" if notfound is an error
whitespace correction
Merge pull request #36 from Trott/notfound

treat `notfound` as an error if it applies to an explicitly-specified script