Fixed setup file to work with datasets.

The setup.py file did not register the datasets module properly. This is
now fixed.

Author: pbugnion

setup.py

@@ -127,7 +127,9 @@ def write_readme():
           data_files=[(os.path.join(ipython_dir, "nbextensions/gmaps_js"),
               ["gmaps/js/heatmap_view.js"])],
           classifiers=classifiers,
-          packages=["gmaps"],
+          packages=["gmaps", "gmaps.datasets"],
+          package_dir={"gmaps.datasets" : "gmaps/datasets" },
+          package_data={"gmaps.datasets": ["metadata.yaml","data/*.csv"]},
           url=r"https://github.com/pbugnion/gmaps",
           license="BSD License", 
           platforms=["Linux", "Mac OS", "Windows"]