fix: Packaging the tests, or not (#287)

* exclude tests from binary distribution

* include tests in source distribution

Author: dimbleby

MANIFEST.in

@@ -0,0 +1 @@
+graft tests/

setup.py

@@ -15,7 +15,7 @@
     author_email="eric@ionrock.org",
     url="https://github.com/ionrock/cachecontrol",
     keywords="requests http caching web",
-    packages=setuptools.find_packages(),
+    packages=setuptools.find_packages(exclude=["tests", "tests.*"]),
     package_data={"": ["LICENSE.txt"]},
     package_dir={"cachecontrol": "cachecontrol"},
     include_package_data=True,