Revert "add gpg plugin"

din't help

This reverts commit b141467.

project/plugins.sbt

@@ -1,13 +1,10 @@
 resolvers ++= Seq(
   "lessis" at "http://repo.lessis.me",
-  "coda" at "http://repo.codahale.com",
-  Resolver.url("sbt-plugin-releases", new URL("http://scalasbt.artifactoryonline.com/scalasbt/sbt-plugin-releases/"))(Resolver.ivyStylePatterns)
+  "coda" at "http://repo.codahale.com"
 )
 
 addSbtPlugin("me.lessis" % "ls-sbt" % "0.1.1")
 
 addSbtPlugin("net.databinder" % "conscript-plugin" % "0.3.3")
 
 libraryDependencies <+= sbtVersion("org.scala-tools.sbt" %% "scripted-plugin" % _)
-
-addSbtPlugin("com.jsuereth" % "xsbt-gpg-plugin" % "0.5")