[Add] phonegap-plugin-contentsync 1.3.0

[macdonst]

Updating the Specs with the latest content sync plugin.

[CocoaPodsBot]

Back in early 2014 we launched CocoaPods Trunk. Trunk is the only way that you can submit pods to CocoaPods, we do not accept pull requests to the CocoaPods Specs repo, and so this is being auto-closed. Please see #12199 for more info.

• To push a new version to trunk, you can use pod trunk push.
• You cannot amend an existing pod, however you can delete and deprecate a pod. You need to be using CocoaPods 1.0 to have access to pod trunk delete and pod trunk deprecate. People may be relying on your pod version, so use these with caution.
• If you don't have permission to update a pod that you own, please file a claim on trunk.