Update to Version 1.0.3 (#12)

This Release removes production logging thanks to #11 .

Added Carthage, Swift Package Manager support

This Release adds Carthage, Swift Package Manager support.

Some extra changes include:

• Adding macOS, tvOS, watchOS support across Cocoapods, Carthage and Swift Package Manager.
• Updating travis to test macOS, tvOS and watchOS.
• Updating podspec to 1.0.2.

Add support to compile for Swift 4.0

This Release adds support for Swift 4.0.

A few overflow calculating methods are changed in Swift 4.0. This release updates the incompatible methods.