Split up extra requirements away from the rest of the project.

Add setup.py for PyPI distribution.
Enhance Invoke tasks.

requirements/development.txt

@@ -1,4 +1,3 @@
 # Requirements for developing the justCheckers app
 Sphinx>=1.2.2
 nose>=1.3.0
-

requirements/web.txt

@@ -0,0 +1,2 @@
+# Requirements for the web front for justCheckers
+Flask>=0.10

setup.py

@@ -0,0 +1,37 @@
+# coding=utf-8
+import re
+
+from setuptools import setup, find_packages
+
+
+def gather_requirements(filename='requirements.txt'):
+    """
+    Gather the requirements from a requirements file.
+
+    :param filename: The name of the file.
+    """
+    with open(filename) as req_file:
+        raw_requirements = req_file.readlines()
+
+    return [requirement.strip()
+            for requirement in raw_requirements
+            if requirement.strip() and not re.match('#|-(?!e)', requirement)]
+
+setup(
+    name='justcheckers',
+    version='0.5.0',
+    packages=['justcheckers'],
+    url='http://justcheckers.org/',
+    license='Affero GPL v3',
+    author='Dorian Pula',
+    author_email='dorian.pula@gmail.com',
+    description='An advanced cross-platform checkers game.',
+
+    install_requires=gather_requirements(),
+    extras_requires={
+        'web': gather_requirements('requirements/web.txt'),
+    },
+
+    packages=find_packages('justcheckers'),
+    include_package_data=True,
+)

tasks.py

@@ -3,15 +3,19 @@ from os import path
 
 from invoke import task, run
 
+
 @task
 def docs():
+    """Build Sphinx documentation."""
     build_dir = '_build'
     if not path.exists(build_dir):
         os.mkdir(build_dir)
     run('sphinx-build -b slides . _build')
 
+
 @task
 def clean():
+    """Clean generated files."""
     run('rm *.pyc')
     run('rm _build -rv')