Support SPM and Update LoadMore functionality

• Adjust the project structure to be compatible with Swift Package Manager (SPM)
• Address the issue related to LoadMore functionality.

Update Swift 4.2

1.2.0

Set minimum version require to iOS 9.0

1.1.2

Release version 1.1.1

Fix bug layout for animator. The spinner can't be layout center of view.

Release version 1.1.0

• Support Swift Package Manager
• Add travis

Release version 1.0.0

• Pull to refresh and load more feature
• Support customize UI