adding specs for rels/alternates
modifying existing test JSON output to add blank rel hashes

rel: {} is required by the spec even if it is empty
modified collection.rb to parse rels and alternates

in order to parse relative URLs in rels, we need to parse the base/@href of
the page if there, or to pass the URL in, so added the relevant stuff to support
that.
updated README to move rels into supported section
omitting the nil - breaking the Travis build
Fix a couple of minor issues in the README.
Update some dependencies.

Tests still pass, I'm going to call it good.  If you build a new app
today, you'll have a hard time with that version of activesupport and
nokogiri.
Merge pull request #13 from G5/readme_fixes

Fix a couple of minor issues in the README.
Merge pull request #14 from G5/dependency_updates

Update some dependencies.
Merge pull request #12 from tommorris/rels-alternates

Added support for rel and alternates
Don't explode when a rel attribute exists without a base tag.

It tries to build an absolute URL for link tags that contain a rel
attribute and a relative URL, using the <base> tag to decide what to
prefix the relative URLs with.  It's very common for people to omit the
base tag and to use rel attributes in stylesheets, and that blows up the
parser.

Now we don't attempt to build absolute URLs when the base URL can't be
determined.
Merge pull request #15 from G5/drop-the-base

Don't explode when a rel attribute exists without a base tag.
normalizes rels urls in issue https://github.com/G5/microformats2/issues/16
add comment for clarity for issue https://github.com/G5/microformats2/issues/17
Simplify Microformats::Collection#absolutize
Merge pull request #19 from G5/rel-alternates-tests

Adds rel="alternates" clarity comment
Merge pull request #18 from G5/normalize-rel-urls

Normalizes rels urls
Normalize u-* property values
Update README
Normalize u-* property values for implied properties