Localization Fixes and Device Compatibility Check

• Unit tests for updating
• Unit tests for localization
• Fixes issues with Portuguese (Brazil), Portuguese (Portugal), Hungarian, and Italian localizations
• Support for showing the update alert only if the app update is compatible with the version of iOS that's on the device.

PR 63 and 64

• Accepted PR #63, which removes a redundant and unnecessary check.
• Augmented #63 with #64, which also simplifies Singleton initialization method.

Changes to Protocol and AppID

Accepted PRs

#54, #55, #56

TL;DR

• Siren uses your app's bundle identifier to perform a version check. The appID param is now used by Siren under the hood. It'll throw an error if you try to set it as it's privately scoped.
• SirenDelegate now sets default empty implementations of all six methods. Therefore, the @objc attribute and optional keyword have been removed as all SirenDelegate methods are now optional by default.
• Signature change from sirenDidShowUpdateDialog() to sirenDidShowUpdateDialog(alertType: SirenAlertType)

Long Version

• As of v0.8.0, Siren is now able to check if your users are using the current version of your app using the app's bundle identifier, which is accessible through the NSBundle API. Instead of removing/deprecating appID, it is still storing your app's iTunes Connect appID, but it is now determined the appID dynamically from the results of the iTunes Lookup API call. Once it's determined, the appID is stored within Siren and used to launch the App Store page of your app when needed.
• Removed @objc attribute from SirenDelegate.
• Removed optional keyword from all SirenDelegate methods.
• SirenDelegate now sets default empty implementations of all six methods.
• Signature change from sirenDidShowUpdateDialog() to sirenDidShowUpdateDialog(alertType: SirenAlertType)

Error Handling and Networking Refactor

In #49, I took the liberty of:

• Added error handling, using both NSErrors and try-catch
• Networking is now done using iOS 8+ APIs
• Improved code readability, scoping and added more lazily instantiated variables

Exposed currentAppStoreVersion

I've exposed a public getter for currentAppStoreVersion in #47.

0.6.6

Added Swift Package manager Support

0.6.5

Added Carthage Support

Fixed issue with daysSinceLastVersionCheckDate method

• #40 (Thanks to @Maxim-Inv)

0.6.3

Accepted PR #108 (Harpy) from @jkandzi

0.6.2

• Added Armenian Localization: Vahan Margaryan for Pull Request #37