fix for r509 0.9 API
increment version
change to using hexserial and write pem to log if there's an error
Merge branch 'master' of github.com:reaperhulk/r509-middleware-certwriter

* 'master' of github.com:reaperhulk/r509-middleware-certwriter:
  Helping Travis.
  Added dependencies to gemspec
  Add redcarpet to Gemfile

Conflicts:
	lib/r509/middleware/certwriter/version.rb
Merge pull request #1 from reaperhulk/master

r509 0.9 compatibility