Bump sbt to 1.1.4, bump some sbt plugins.

Author: analytically

project/build.properties

@@ -1 +1 @@
-sbt.version=1.1.1
+sbt.version=1.1.4

project/plugins.sbt

@@ -1,11 +1,11 @@
 resolvers += Resolver.typesafeRepo("releases")
 
-addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.1.0")
+addSbtPlugin("com.jsuereth" % "sbt-pgp" % "1.1.1")
 
 addSbtPlugin("org.scalariform" % "sbt-scalariform" % "1.8.2")
 
-addSbtPlugin("com.github.gseitz" % "sbt-release" % "1.0.7")
+addSbtPlugin("com.github.gseitz" % "sbt-release" % "1.0.8")
 
-addSbtPlugin("com.typesafe.sbt" % "sbt-osgi" % "0.9.2")
+addSbtPlugin("com.typesafe.sbt" % "sbt-osgi" % "0.9.3")
 
 addSbtPlugin("com.scalapenos" % "sbt-prompt" % "1.0.2")