update metadata homepage

Author: Buck Ryan

setup.py

@@ -8,7 +8,7 @@
     author="Buck Ryan",
     author_email="buck@buckryan.com",
     license="MIT",
-    url="https://github.com/banga/powerline-shell",
+    url="https://github.com/b-ryan/powerline-shell",
     classifiers=[
         "Programming Language :: Python :: 2",
         "Programming Language :: Python :: 2.7",