Merge pull request #791 from typelevel/update/compilerplugin-0.11.20

Update compilerplugin, scalapb-runtime, ... to 0.11.20

Author: ahjohannessen

project/plugins.sbt

@@ -7,4 +7,4 @@ addSbtPlugin("com.timushev.sbt" % "sbt-updates" % "0.6.4")
 
 addSbtPlugin("com.thesamet" % "sbt-protoc" % "1.0.8") // Because sbt-protoc-gen-project brings in 1.0.4
 addSbtPlugin("com.thesamet" % "sbt-protoc-gen-project" % "0.1.8")
-libraryDependencies += "com.thesamet.scalapb" %% "compilerplugin" % "0.11.19"
+libraryDependencies += "com.thesamet.scalapb" %% "compilerplugin" % "0.11.20"