Improve setup

MANIFEST.in

@@ -0,0 +1,2 @@
+include LICENSE
+include requirements.txt

setup.py

@@ -5,27 +5,43 @@
 from os import path
 from setuptools import setup
 
-_version_re = re.compile(r'__version__\s+=\s+(.*)')
+PACKAGE_NAME = "protowhat"
+REQUIREMENT_NAMES = ["markdown2", "jinja2"]
 
-PACKAGE_NAME = 'protowhat'
 HERE = path.abspath(path.dirname(__file__))
-with open(path.join(HERE, 'README.md'), encoding='utf-8') as fp:
+VERSION_FILE = path.join(HERE, PACKAGE_NAME, "__init__.py")
+REQUIREMENTS_FILE = path.join(HERE, "requirements.txt")
+README_FILE = path.join(HERE, "README.md")
+
+with open(VERSION_FILE, encoding="utf-8") as fp:
+    _version_re = re.compile(r"__version__\s+=\s+(.*)")
+    VERSION = str(ast.literal_eval(_version_re.search(fp.read()).group(1)))
+with open(REQUIREMENTS_FILE, encoding="utf-8") as fp:
+    req_txt = fp.read()
+    _requirements_re_template = r"^({}(?:\s*[<>=]+\s*\S*)?)\s*(?:#.*)?$"
+    REQUIREMENTS = [
+        re.search(_requirements_re_template.format(requirement), req_txt, re.M).group(0)
+        for requirement in REQUIREMENT_NAMES
+    ]
+with open(README_FILE, encoding="utf-8") as fp:
     README = fp.read()
-with open(path.join(HERE, PACKAGE_NAME, '__init__.py'), 'rb') as fp:
-    VERSION = str(ast.literal_eval(_version_re.search(
-        fp.read().decode('utf-8')).group(1)))
 
 setup(
-	name=PACKAGE_NAME,
-	version=VERSION,
-	packages=['protowhat', 'protowhat.checks'],
-	install_requires=['markdown2', 'jinja2'],
-        description = 'Prototype package for submission correctness testing',
-        long_description=README,
-        long_description_content_type='text/markdown',
-        license='GNU version 3',
-        author='DataCamp',
-        author_email='[email protected]',
-        maintainer='Filip Schouwenaars',
-        maintainer_email='[email protected]',
-        url = 'https://github.com/datacamp/protowhat')
+    name=PACKAGE_NAME,
+    version=VERSION,
+    packages=[PACKAGE_NAME, "{}.checks".format(PACKAGE_NAME)],
+    install_requires=REQUIREMENTS,
+    description="Prototype package for submission correctness testing",
+    long_description=README,
+    long_description_content_type="text/markdown",
+    author="Filip Schouwenaars",
+    author_email="[email protected]",
+    maintainer="Jeroen Hermans",
+    maintainer_email="[email protected]",
+    url="https://github.com/datacamp/protowhat",
+    classifiers=[
+        "Programming Language :: Python :: 3",
+        "License :: OSI Approved :: GNU Affero General Public License v3",
+        "Operating System :: OS Independent",
+    ],
+)