Swift 5 Updates + SPM Support

Update framework version for new cocoa pods release
Run project through new cocoa pods version. this changes pods files and it's related script
drop support for iOS 8. Minimum iOS version supported is iOS 9
Provide support for Swift package manager
Update readme and contact for maintenance

Swift 4.2 compatibility

Updates for Swift 4.2 (#26)

* Swift 4.2 fixes

* version 0.2.2

* fix example

* try fix travis build

Swift 4 compatibility

0.2.0

Release 0.2.0

Swift 3 compatibility

• Added swift 3 compatibility (#13)

0.0.7

• Added the steps center points (see #11)

0.0.6

• Fixed a rendering issue (#10, thanks @hernangonzalez & @AlexanderNorway)
• Removed internal deprecated calls (#9, thanks @aschober)

0.0.5

• Fixed an orientation issue

0.0.4

• Added code exemple initialisation
• Fixed potential retain cycle issue

0.0.3

• Swift 2 compatibility ( thanks to @edwardmarks )
• The radius is now configurable ( thanks to @edwardmarks )
• Added Exemple project

0.0.2

• Fixed delegate call issues
• Fixed Xcode 6.3 beta3 building issues