Bumped version to 0.4.4

Add Swift version to podspec file + format & lint the code

Cocoapods 1.4.0 includes the ability to specify the Swift version in the podspec (previously this could be done by creating a separate file in the repo). This allows Cocoapods to know which target to set for the Pod - instead of going for a default value, which can cause troubles when mixing Swift 4 and 3 code.

This change adds the Swift version to the Podspec.

The other changes includes some basic formatting and linting (mostly removal of whitespace and following Swift styleguides).

Also updates the Podspec version.

Made respondToSwipe method open and only requiring a direction.

The reason is that we might want to call it programatically, for example when pressing a button.

Change default implementatino of isUndoable to true

Add unlimited undo functionality

Update version to fix custom size support

Added support for any custom card size

Readded code to handle rapid swicks

At the moment we only support this when horizontal swipes is the only swipe direction allowed.

Add documentation and commentsto relevant methods and the example pro…

…ject.