Add support for Kotlin 1.7

[jeffboutotte]

The type signature for parseCommandLineArguments changed with Kotlin 1.7. To preserve support for 1.6.x and below still call the method with its old signature if the version of Kotlin is configured to be less than 1.7.0 but call the method with a newer signature if using Kotlin 1.7.0+.

Additional changes:

• Drop the android tests since sbt-android still isn't updated to sbt 1.0 and it seems odd this repository has tests for that plugin as well
• Update the default JVM target to 1.8
• Adds tests for Kotlin 1.5, 1.6 & 1.7

[chameleon82]

Hi @pfn , please help with this important change.