Updates the project to use the v1.6.20 Kotlin compiler, but sets options to preserve compatibility with Kotlin 1.3 (the version of Kotlin that we were previously using).
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.
Issue #, if available:
Fixes #46
Description of changes:
Updates the project to use the v1.6.20 Kotlin compiler, but sets options to preserve compatibility with Kotlin 1.3 (the version of Kotlin that we were previously using).
By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.