Update Supported Swift Versions

This patch was authored and released by @0xTim.

This removes support for Swift 5.2 and Swift 5.3, making Swift 5.4 the earliest supported version as
announced

async/await

This patch was authored and released by @0xTim.

Adds async APIs to Application.APNS and Request.APNS to match existing EventLoopFuture APIs

Allow multiple notifications to be sent

This patch was authored by @MrWoWander and released by @0xTim.

Adds a new batchSend API to allow multiple notifications to be sent with the same call

Licence the project as MIT

This patch was authored by @PSchmiedmayer and released by @0xTim.

Adds the MIT License

2.0.0

bump upstream release.

Fix infinite recursion on APNSwift release

Fix for infinite loop (#27)

Fix for https://github.com/kylebrowning/APNSwift/issues/100

APNS 1.0.0

This patch was authored and released by @tanner0101.

Docs:
https://docs.vapor.codes/4.0/apns/

More information on Vapor 4 official release:
https://forums.swift.org/t/vapor-4-official-release-begins/34802

Vapor is out of RC, require the released version

This patch was authored by @gwynne and released by @kylebrowning.

No additional notes.

Release Candidate 1

Upgrades APNs to APNSwift 2.0

Beta 3

• Match Vapor's new minimum OS requirement
• Bump minimum required version of Vapor
• Major beta server due to compatibility break of new minimum OS requirement. There are no actual changes to this driver or to the underlying APNS implementation.

This patch was authored by @gwynne and released by @0xTim.