Update sbt-header to 5.7.0 (#153)

Author: scala-steward

build.sbt

@@ -8,6 +8,6 @@ licenses            := Seq(("Apache-2.0", url("https://www.apache.org/licenses/L
 developers          := List(Developer("", "", "", url("https://scala-lang.org")))
 
 addSbtPlugin("com.typesafe.sbt" % "sbt-osgi" % "0.9.6")
-addSbtPlugin("de.heikoseeberger" % "sbt-header" % "5.6.5")
+addSbtPlugin("de.heikoseeberger" % "sbt-header" % "5.7.0")
 addSbtPlugin("com.github.sbt" % "sbt-ci-release" % "1.5.10") // set version, scmInfo, publishing settings
 addSbtPlugin("ch.epfl.scala" % "sbt-version-policy" % "2.0.1")  // brings in MiMa