BLD: included pandas.api.* in setup.py (#13640)

Author: gfyoung

setup.py

@@ -547,6 +547,9 @@ def pxd(name):
       maintainer=AUTHOR,
       version=versioneer.get_version(),
       packages=['pandas',
+                'pandas.api',
+                'pandas.api.tests',
+                'pandas.api.types',
                 'pandas.compat',
                 'pandas.compat.numpy',
                 'pandas.computation',