Add support for windows and multiple os

[oshai]

will build on windows,linux and mac.

[oshai]

It looks like Java is not supported on windows in Travis, so another alternative is to try circleci.

[oshai]

circle ci only support java 11 out of the box, so need to explicitly compile to java 8:
https://stackoverflow.com/questions/49509330/kotlin-compile-to-java-1-8

[petertrr]

Hey @oshai , have you considered using github actions for releases? You can use linux, macos and windows runners in the same workflow, and Java versions can be configured using actions/setup-java.
I have set up releasing to Maven Central using github actions recently, if you are interested you can check out my config: PublishingConfiguration.kt, release.yml.

[oshai]

implemented in another cl in 2.1.15