Bump kotlinVersion from 1.3.72 to 1.4.0 (#452)

Bumps `kotlinVersion` from 1.3.72 to 1.4.0.

Updates `kotlin-stdlib` from 1.3.72 to 1.4.0
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/v1.4.0/ChangeLog.md)
- [Commits](JetBrains/kotlin@v1.3.72...v1.4.0)

Updates `kotlin-gradle-plugin` from 1.3.72 to 1.4.0

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

build.gradle

@@ -8,7 +8,7 @@ ext {
   compileSdkVersion = 28
   buildToolsVersion = '28.0.3'
   gradleVersion = '4.6'
-  kotlinVersion = '1.3.72'
+  kotlinVersion = '1.4.0'
   detektVersion = '1.0.0.RC6-1'
 }