add python markers, enable universal wheels

setup.cfg

@@ -0,0 +1,2 @@
+[bdist_wheel]
+universal = 1

setup.py

@@ -1,12 +1,23 @@
 #!/usr/bin/env python
+import os
 from setuptools import setup
 
+CWD = os.path.dirname(os.path.realpath(__file__))
+
+
+def read(*path):
+    filename = os.path.join(CWD, *path)
+    with open(filename, "r") as f:
+        return f.read()
+
+
 setup(
     name="mnemonic",
     version="0.19",
     author="Trezor",
     author_email="info@trezor.io",
     description="Implementation of Bitcoin BIP-0039",
+    long_description=read("README.rst"),
     url="https://github.com/trezor/python-mnemonic",
     packages=["mnemonic"],
     package_data={"mnemonic": ["wordlist/*.txt"]},
@@ -16,5 +27,7 @@
         "Operating System :: POSIX :: Linux",
         "Operating System :: Microsoft :: Windows",
         "Operating System :: MacOS :: MacOS X",
+        "Programming Language :: Python :: 2",
+        "Programming Language :: Python :: 3",
     ],
 )