Fix license checks in headers for sbt buid

[yruslan]

Background

Currently, Cobrix copyright headers contain year ranges, e.g. 2018-2019. According to @GeorgiChochov,

sbt headerCheck doesn't work with 2018-2019 in the license header, expected only 2018 and I can't override it for some reason

Feature

When sbt-header plugin allows a workaround for ranged years in copyright headers, add a chacking task to the sbt build.