README.md in jdk10 branch says it requires jvmTarget 1.8

[travisfw]

The Important Version Note section either needs to be updated for the jdk10 branch or just deleted.

[SchweinchenFuntik]

this refers to Kotlin, which version of Java you want to compile into, Kotlin supports target 1.6 (by default) so it is indicated that 1.8 should be specified. Until recently, a target higher than 1.8 was meaningless, Kotlin actually compiled in 1.8