Update the package version to 0.4.0

Author: NicholasMamo

setup.py

@@ -5,7 +5,7 @@
 
 setuptools.setup(
     name="multiplex-plot", # Replace with your own username
-    version="0.3.7",
+    version="0.4.0",
     author="Nicholas Mamo",
     author_email="nicholasmamo@gmail.com",
     description="Multiplex: visualizations that tell stories",