Cleanup setup.py

- Read requirements from requirements.txt
- Support both setuptools and distutils
- Use wrapper for opening the correct file for requirements.txt and the readme
- Import version from package
- Hardcode package list
- Avoid reading in entire license file when specifying the license attribute

 #!/usr/bin/env python
 
-from setuptools import setup, find_packages
-
+from kappa import __version__
 import os
 
-requires = [
-    'boto3>=1.2.2',
-    'placebo>=0.4.1',
-    'click>=5.0',
-    'PyYAML>=3.11'
-]
+try:
+    from setuptools import setup
+except ImportError:
+    from distutils.core import setup
+
+
+def open_file(fname):
+    return open(os.path.join(os.path.dirname(__file__), fname))
 
 
 setup(
     name='kappa',
-    version=open(os.path.join('kappa', '_version')).read().strip(),
+    version=__version__,
     description='A CLI tool for AWS Lambda developers',
-    long_description=open('README.rst').read(),
+    long_description=open_file('README.rst').read(),
+    url='https://github.com/garnaat/kappa',
     author='Mitch Garnaat',
     author_email='mitch@garnaat.com',
-    url='https://github.com/garnaat/kappa',
-    packages=find_packages(exclude=['tests*']),
+    license='Apache License 2.0',
+    packages=['kappa', 'kappa.scripts'],
     package_data={'kappa': ['_version']},
     package_dir={'kappa': 'kappa'},
     entry_points="""
         [console_scripts]
         kappa=kappa.scripts.cli:cli
     """,
-    install_requires=requires,
-    license=open("LICENSE").read(),
+    install_requires=open_file('requirements.txt').readlines(),
+    test_suite='tests',
+    include_package_data=True,
+    zip_safe=True,
     classifiers=(
         'Development Status :: 3 - Alpha',
         'Intended Audience :: Developers',