Add a package_dir attribute

Since this Python module doesn't use a standard src-layout, setuptools
gets confused and is unable to locate the packages to be included.
Since this "Python module" is really just a collection of scripts, we
can tell setuptools to restrict itself to project_setup/scripts.

This is yet another reason why #33 is a good idea.

setup.py

@@ -62,6 +62,7 @@ def package_vars(version_file):
     python_requires=">=3.6",
     # What does your project relate to?
     keywords="documentation",
+    package_dir={"": "project_setup/scripts"},
     install_requires=[
         "boto3",
         "docopt",