Improve pull request URL regexp

 - use a regexp literal and avoid escaping forward slashes
 - escape the period in "github.com"
 - match only hex characters in the commit part
 - allow hyphen in usernames and repo names, matching what we allow for
   tap names
 - avoid unnecessary capture
Use if-else instead of postfix unless
Remove the patch from the cache after applying it
Remove a conditional and always pass the spec to satisfied_requirements
Don't mess with stdout when writing build config to a file
Allow verbose config to be written to any IO object
brew-gist-logs: dump config directly
Remove intermediate method