Kotlin sample app

[Simply007]

Motivation

Kotlin sample app showcasing Kotlin coroutines with Kentico Kontent Delivery SDK.

Related to #113

Checklist

• [ ] Code follows coding conventions held in this repo
• [ ] Automated tests have been added
• [ ] Tests are passing
• [ ] Docs have been updated (if applicable)
• [ ] Temporary settings (e.g. variables used during development and testing) have been reverted to defaults

How to test

If manual testing is required, what are the steps?

[Simply007]

After merge:

1. release beta of the deliverySDK
   • ✔ https://bintray.com/kentico/kontent-java-packages/kontent-delivery/4.1.0-beta.2
2. @makma - check if the delivery SDK is working
   • Strongly type converter was changed
   • Thymeleaf configuration
   • commits https://github.com/Kentico/kontent-java-packages/commit/c8729c06b86bb022e200f0951dbb6af719b78598 https://github.com/Kentico/kontent-java-packages/commit/c8e04cbfcc2c6a7ddd4f848ec95c4fe069a7c19e
3. release final