convert to package so that the stub file can be installed properly

Author: srittau

NEWS.rst

@@ -1,6 +1,10 @@
 News in asserts 0.7.1
 =====================
 
+* Distribute as wheel.
+* asserts is now a package, instead of a module.
+
+
 News in asserts 0.7.0
 =====================
 

asserts.py renamed to asserts/__init__.py

@@ -2,7 +2,6 @@
 
 import os
 from setuptools import setup
-import sys
 
 
 def read(fname):
@@ -17,11 +16,8 @@ def read(fname):
     author="Sebastian Rittau",
     author_email="srittau@rittau.biz",
     url="https://github.com/srittau/python-asserts",
-    py_modules=["asserts", "test_asserts"],
-    data_files=[(
-        "lib/python{}.{}/site-packages".format(*sys.version_info[:2]),
-        ["asserts.pyi"],
-    )],
+    packages=["asserts"],
+    package_data={"asserts": ["*.pyi"]},
     python_requires=">=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*",
     license="MIT",
     classifiers=[