vendor: Update cobra and pflag
vendor: Update cobra and pflag

* Faster help message
* Faster docs
* Adds help flag in usage

fedelibre/hugo,digitalcraftsman/hugo,gohugoio/hugo,mitchchn/hugo,mdhender/hugo,fedelibre/hugo,mdhender/hugo,mdhender/hugo,gohugoio/hugo,fedelibre/hugo,anthonyfok/hugo,anthonyfok/hugo,fedelibre/hugo,mitchchn/hugo,gohugoio/hugo,digitalcraftsman/hugo,mdhender/hugo,anthonyfok/hugo