[BUILD] Minor updates to the build.

Author: eaplatanios

build.sbt

@@ -19,8 +19,8 @@ import sbtrelease.Vcs
 
 import scala.sys.process.Process
 
-scalaVersion in ThisBuild := "2.12.4"
-crossScalaVersions in ThisBuild := Seq("2.11.12", "2.12.4")
+scalaVersion in ThisBuild := "2.12.7"
+crossScalaVersions in ThisBuild := Seq("2.11.12", "2.12.7")
 
 organization in ThisBuild := "org.platanios"
 
@@ -354,7 +354,7 @@ lazy val publishSettings = Seq(
   publishMavenStyle := true,
   // publishArtifact in Test := false,
   pomIncludeRepository := Function.const(false),
-  publishTo := Some(
+  publishTo in ThisBuild := Some(
     if (isSnapshot.value)
       Opts.resolver.sonatypeSnapshots
     else

project/plugins.sbt

@@ -33,8 +33,8 @@ addSbtPlugin("com.eed3si9n" % "sbt-unidoc"     % "0.4.1")
 addSbtPlugin("com.47deg"    % "sbt-microsites" % "0.7.18")
 
 // Packaging and publishing related plugins
-addSbtPlugin("com.github.gseitz" % "sbt-release"  % "1.0.8")
-addSbtPlugin("com.jsuereth"      % "sbt-pgp"      % "1.1.1")
+addSbtPlugin("com.github.gseitz" % "sbt-release"  % "1.0.9")
+addSbtPlugin("com.jsuereth"      % "sbt-pgp"      % "2.0.0-M2")
 addSbtPlugin("org.xerial.sbt"    % "sbt-sonatype" % "2.0")
 
 // Generally useful plugins