Use more recent Scala, sbt and sbt-assembly versions

Scala: 2.11.12
sbt: 1.3.9
sbat-assembly: 0.14.7

Change-Id: I5c6ce3dc34f303d1fcdb3eb32a7c8401f37c78b0
diff --git a/project/SharedSettings.scala b/project/SharedSettings.scala
index 64f89b6..bfc3b4d 100644
--- a/project/SharedSettings.scala
+++ b/project/SharedSettings.scala
@@ -29,7 +29,7 @@
   private val dockerRepositoryPrefix = "gerrit-analytics-etl"
 
   lazy val commonSettings: Seq[Def.Setting[_]] = Seq(
-    scalaVersion := "2.11.8",
+    scalaVersion := "2.11.12",
     organization := "gerritforge",
     parallelExecution in Test := false,
     fork in Test := true,
diff --git a/project/assembly.sbt b/project/assembly.sbt
index 74adde3..d95475f 100644
--- a/project/assembly.sbt
+++ b/project/assembly.sbt
@@ -1 +1 @@
-addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.13.0")
+addSbtPlugin("com.eed3si9n" % "sbt-assembly" % "0.14.7")
diff --git a/project/build.properties b/project/build.properties
index 64317fd..06703e3 100644
--- a/project/build.properties
+++ b/project/build.properties
@@ -1 +1 @@
-sbt.version=0.13.15
+sbt.version=1.3.9