Update sbt-mima-plugin to 1.1.6 (#457)

Author: softwaremill-ci

project/plugins.sbt

@@ -8,6 +8,6 @@ addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-publish" %
 addSbtPlugin("com.softwaremill.sbt-softwaremill" % "sbt-softwaremill-browser-test-js" % sbtSoftwareMillVersion)
 
 addSbtPlugin("org.jetbrains" % "sbt-ide-settings" % "1.1.0")
-addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "1.1.5")
+addSbtPlugin("com.typesafe" % "sbt-mima-plugin" % "1.1.6")
 
 addSbtPlugin("pl.project13.scala" % "sbt-jmh" % "0.4.8")