AccordionSwift Versions Save

• Decrease the minimum deployment target to iOS 10.
• Add the ability to toggle between having multiple items open at once or to have a single item open at a time.
• Add Carthage support.
• Added scrollViewDidScroll(_:) method into the DataSourceProvider class.

• Fix an issue causing the Example app couldn’t be loaded in a device
• Remove the deprecated .swift-version in favor of the swift_version spec
• Increase the minimum deployment target to 11.4
• Update the project to Xcode 10.2.1 and Swift 5

• Cells not being expanded after a Parent cell with no Childs #42.
• Crash when Parent cell doesn't have any cell #39.
• Add support for custom height in each cell #44.

Big refactor using protocol-oriented programming.