Prepare for Release 3.3.0

build.sbt: Remove SNAPSHOT.

DAFFODIL-2677
diff --git a/build.sbt b/build.sbt
index 864ff7c..cb242d7 100644
--- a/build.sbt
+++ b/build.sbt
@@ -152,7 +152,7 @@
 
 lazy val commonSettings = Seq(
   organization := "org.apache.daffodil",
-  version := "3.3.0-SNAPSHOT",
+  version := "3.3.0",
   scalaVersion := "2.12.15",
   crossScalaVersions := Seq("2.12.15"),
   scalacOptions ++= buildScalacOptions(scalaVersion.value),