Fix links in README
Remove guard, which is causing problems on 1.8.7
Update rvm/rbenv versions to 1.9.3
Fix TImezone handling when localtime is in UTC

Fun quirk: travis CI runs UTC on their servers, so it caught this bug in
ruby 1.9.3 and up. If the localtime is in UTC, we don't need a daylight
savings offset, so the values should be correct in both UTC and offset
zones

  verified with
   * TZ="America/Chicago" rake spec
   * TZ=UTC rake spec
Bumped version v1.3.13
make SharedListing attributes match API
updated tests for SharedListing include new attributes
Merge pull request #71 from terryroe/master

make SharedListing attributes match API
Bumped version v1.3.14
FLEX-613 Fix ListingCart path for contact carts

The ListingCart#add_listing instance method previously did not work
correctly when accessing carts as an agent on behalf of a contact. This
changeset fixes that by correcting the path method when a contact ID is
present

closes #72
Bumped version v1.3.15
Added second parameter to SparkApi::Models:Base#respond_to? signature.
Merge pull request #76 from valeronm/second_parameter_to_respond_to

Added second parameter to SparkApi::Models:Base#respond_to? signature.