Clear-out mimaPreviousVersions

In previous commit, binary compatability with previous version is broken because we added a new function to a trait.
Therefore, we need to clear-out the mimaPreviousVersions.

project/BuildSettings.scala

@@ -68,7 +68,7 @@ object BuildSettings {
   // clear-out mimaBinaryIssueFilters and mimaPreviousVersions.
   // Otherwise, add previous version to set without
   // removing other versions.
-  val mimaPreviousVersions = Set("3.0.0")
+  val mimaPreviousVersions = Set()
 
   lazy val mimaSettings = Seq(
     mimaPreviousArtifacts := {