update: Add setup.py

* Add the first version of setup.py in order to simplify creation of a
  real `wikiextractor` command.

Signed-off-by: mr.Shu <mr@shu.io>

setup.py

@@ -0,0 +1,21 @@
+from setuptools import setup
+
+setup(
+    name='wikiextractor',
+
+    description='A script that extracts and cleans text from a Wikipedia'
+                'database dump',
+    author='Giuseppe Attardi',
+    author_email='attardi@di.unipi.it',
+    version='2.42',
+
+    url='https://github.com/attardi/wikiextractor',
+
+    license="GPL 3.0",
+    keywords=['text', 'nlp'],
+    entry_points={
+        'console_scripts': [
+            'wikiextractor = WikiExtractor:main'
+        ]
+    }
+)