Fix double slash in RSS feed post URLs
Jekyll build

jekyll 1.2.1
Darwin Neologist.local 13.2.0 Darwin Kernel Version 13.2.0: Thu Apr 17 23:03:13 PDT 2014; root:xnu-2422.100.13~1/RELEASE_X86_64 x86_64

Configuration file: /Users/jmah/Documents/Streams/dev-etc/_config.yml
            Source: /Users/jmah/Documents/Streams/dev-etc
       Destination: /Users/jmah/Documents/Streams/dev-etc/_site
      Generating... Configuration file: /Users/jmah/Documents/Streams/dev-etc/_config.yml
done.