Change build version number for 0.3.0-RC1 release

Author: felixmulder

project/Build.scala

@@ -40,7 +40,7 @@ object Build {
   val dottyOrganization = "ch.epfl.lamp"
   val dottyGithubUrl = "https://github.com/lampepfl/dotty"
   val dottyVersion = {
-    val baseVersion = "0.3.0"
+    val baseVersion = "0.3.0-RC1"
     val isNightly = sys.env.get("NIGHTLYBUILD") == Some("yes")
     val isRelease = sys.env.get("RELEASEBUILD") == Some("yes")
     if (isNightly)