Configuring versionIncrementer is cumbersome in Kotlin DSL

[radoslaw-panuszewski]

Expected behavior

scmVersion {
    versionIncrementer = PredefinedVersionCreator.INCREMENT_MINOR.versionIncrementer
}

Current behavior

scmVersion {
    versionIncrementer = VersionProperties.Incrementer { it.currentVersion.incrementMinorVersion() }
}

Context

There are 2 interfaces: PredefinedVersionIncrementer.VersionIncrementer and VersionProperties.Incrementer. The latter is exposed to DSL via VersionConfig.getVersionIncrementer() but PredefinedVersionIncrementer implements the former.

The similar config versionCreator has only one interface VersionProperties.Creator and PredefinedVersionCreator implements it. We should do it the same way for versionIncrementer.