Add isExpired method
Updated iOS sample app to use latest API changes.

App wasn't building after a fresh clone.
Use double floor instead of float floor on the double value of the NSTimeInterval to avoid sending duplicate timestamps
Setting observers to nil fixes
https://github.com/AFNetworking/AFOAuth1Client/issues/58
Merge pull request #59 from influitive/develop

Setting applicationLaunchNotificationObserver to nil when done
Merge pull request #53 from rcgroot/master

 avoid sending duplicate timestamps because of rounding error
Merge pull request #50 from zorn/patch-1

Updated iOS sample app to use latest API changes.
Merge pull request #44 from alexanderedge/master

implement expiry method
Bumping AFNetworking version to 1.3.1
Bumping version to 0.2.1
Update Twitter API paths to use API v1.1
Fixing CocoaPods 0.21.0 issues.
improve documentation - describe need for notifier
Escape consumer secret and token secret for implement RFC 5849.
add token storage/retrieval in keychain
Specify AFNetworking ~>1.3 while AFOAuth1Client fails to build against 2.x
Merge pull request #75 from tomburns/master

Specify AFNetworking ~>1.3 while AFOAuth1Client fails to build w/ 2.0.0
[Issue #71] Adding userInfo property to AFOAuth1Token
Minor reformatting
Removing explicit @synthesize declarations