added refresh
removed unused updateIsExpired method
Fixed isFetchable

- Made it use the right property to check for expiry
- Made it volatile, as it depends on a volatile property now
- Added a test for it.
Refactored resourceSpec
Merge pull request #12 from zendesk/shajith/port_fixes

Porting expiry changes
Do not tick the clock when expiring resources.
Merge pull request #13 from zendesk/josh/do_not_tick_on_expire

Do not tick the clock when expiring resources.
Clean up Gemfile.

* Use the Heroku mirror to reduce load on the rubygems.org API
* Drop the rails dependency
* Specify proper gem releases rather than pointing to git repos
Revert back to consistent function definitions.

We changed this when we were fighting with JSHint. Now we've upgraded
to JSHint 1.0 and this is no longer a problem.

To reduce the diff and increase consistency, we're reverting this
change.
Consistent use of `throw`.

Adhering to the `throw` syntax used by `Ember` and other JavaScript
projects.
Adding proper dependencies.

* isFetchable depends on isExpired
* isExpired depends on expireAt
Merge pull request #14 from zendesk/josh/gemfile

Clean up Gemfile.
Adding current release info to the Readme.
Explicitly marking all properties as `cacheable` or `volatile`.
A better description of Ember Resource 2.0 in the Readme.
Merge pull request #16 from zendesk/josh/volatile_cacheable

Explicitly marking all properties as `cacheable` or `volatile`.
Update README.md
Merge branch 'master' into shajith/no_autofetch

Conflicts:
	src/ember-resource.js