Support Swift 4.1

Updated PromiseK for Swift 4.1.

Update OAuthSwift

All warnings caused by the earlier version of OAuthSwift have been fixed.

Remove an unnecessary extension method

Merge pull request #11 from swift-tweets/dev-0.2.1

Remove `replacingOccurrences` of StringExtensions

Promisified APIs with Swift 4

• Swift 4
• Promisified APIs
• Tweets chained by replies

Improvement of code images and bug fix

Merge pull request #9 from swift-tweets/dev-0.1.1

Develop 0.1.1

0.1.1-beta.2

Change the core rendering width

0.1.1-beta

Fix to count URLs like "Swift.org"

0.1.0

Merge pull request #7 from swift-tweets/dev

Develop 0.1.0

0.1.0-beta

Fix synchronization