update tlBaseVersion after release (RustedBones#172)

Author: RustedBones

build.sbt

@@ -5,7 +5,7 @@ val username  = "RustedBones"
 val repo      = "pekko-http-metrics"
 val githubUrl = s"https://github.com/$username/$repo"
 
-ThisBuild / tlBaseVersion    := "2.0"
+ThisBuild / tlBaseVersion    := "2.1"
 ThisBuild / organization     := "fr.davit"
 ThisBuild / organizationName := "Michel Davit"
 ThisBuild / startYear        := Some(2019)