Bump version to 0.4.0

Change-Id: If8b0718f422519f26ae6daae41284ca39d18ddbb
diff --git a/DESCRIPTION b/DESCRIPTION
index 94b1929..71ccfe6 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: idsThemeR
 Type: Package
 Title: Plot themes for the Leibniz Institute for the German Language (IDS)
-Version: 0.3.0
+Version: 0.4.0
 Authors@R:
     c(person(given = "Marc",
              family = "Kupietz",