inconsistent handling of upper/lowercase in RSVP processing

[sknebel]

When an RSVP post is processed, the rsvp value as it appears in the post is taken from the source post (via XRay) and used to create the post type
(/helpers/webmention_processor.rb#L297):

    if rsvp = entry['rsvp']
      phrase = "RSVPed #{rsvp} to"
      link.type = "rsvp-#{rsvp}"

When generating the JSON output, this value is passed through as is (/helpers/formats.rb#L41):

      obj[:activity] = {
        :type => link.type,
        :sentence => link.sentence,
        :sentence_html => link.sentence_html
}

When generating the JF2 output, a specific list of cases is matched (/helpers/formats.rb#L136):

when "rsvp-yes"
    relation = :"rsvp"
    jf2[:rsvp] = "yes"

I believe this explains some of what @tantek has been commenting on over in #64. From https://indieweb.org/rsvp it is not immediately clear to me if rsvp values are supposed to be case-sensitive or not? (@tantek again)

[tantek]

Per http://microformats.org/wiki/h-entry which defines p-rsvp, yes, rsvp values must be parsed case-insensitive.

[aaronpk]

I just pushed a fix to XRay that will convert RSVP values to lowercase, which will help this problem going forward. I also pushed a fix to webmention.io in bfdd4e6 to convert to lowercase.