update sbt 1.3.8 & sbt plugins

Author: giabao

project/build.properties

@@ -1 +1 @@
-sbt.version=1.2.8
+sbt.version=1.3.8

project/plugins.sbt

@@ -1,5 +1,5 @@
-addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.1.1")
+addSbtPlugin("com.jsuereth" % "sbt-pgp" % "2.0.1")
 
-addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.2.2")
+addSbtPlugin("com.geirsson" % "sbt-ci-release" % "1.5.2")
 
-addSbtPlugin("com.typesafe.sbt" % "sbt-osgi" % "0.9.4")
+addSbtPlugin("com.typesafe.sbt" % "sbt-osgi" % "0.9.5")