Update plugin version on README

Fixed removed sbt-scoverage version to the latest. 

Fixes #10

Author: pedrorijo91

README.md

@@ -19,7 +19,7 @@ To start, add the `scoverage` and Codacy sbt plugins into your plugins.sbt file:
 ```sbt
 resolvers += "Typesafe Repository" at "https://repo.typesafe.com/typesafe/releases/"
 
-addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.3.1")
+addSbtPlugin("org.scoverage" % "sbt-scoverage" % "1.3.3")
 
 addSbtPlugin("com.codacy" % "sbt-codacy-coverage" % "1.2.1")
 ```