Migrate to Kotlin, Android X and use latest library versions

[michael-winkler]

This PR migrates the existing project to Kotlin and Android X. It uses also the latest library updates from other depencies.

Implementation:

allprojects {
    repositories {
        maven { url 'https://jitpack.io' }
    }
}

build.gradle:

• implementation 'com.github.Mika-89:QRCodeReaderView:master-SNAPSHOT'

This project should not be dead since there are still devices without google play services support.

[michael-winkler]

@dlazaro66 Please review this PR and feel free to merge it. Thanks.