Bump version to 7.3.0

Author: emontnemery

setup.py

@@ -5,7 +5,7 @@
 
 setup(
     name="PyChromecast",
-    version="7.2.1",
+    version="7.3.0",
     license="MIT",
     url="https://github.com/balloob/pychromecast",
     author="Paulus Schoutsen",