Update general text

Remove obsoleted versions from description.

README.md

@@ -36,7 +36,7 @@ Each of the files should have the following contents.
 
 `project/build.properties`:
 
-    sbt.version=0.13.8
+    sbt.version=1.5.5
 
 `project/build.scala`:
 
@@ -45,12 +45,8 @@ Each of the files should have the following contents.
 
 `project/plugins.sbt`:
 
-     addSbtPlugin("com.typesafe.sbt" % "sbt-pom-reader" % "2.0.0")
-     
+     addSbtPlugin("com.typesafe.sbt" % "sbt-pom-reader" % "x.y.z")
 
-Note: Release candidate `2.1.0-RC2` is available, providing updates to the Maven/Wagon/Aether library versions. (Testing and bug reporting is appreciated!)
-
-     addSbtPlugin("com.typesafe.sbt" % "sbt-pom-reader" % "2.1.0-RC2")
 
 ## Configuring projects