Add check for Python 3 and increment version

setup.py

@@ -1,16 +1,20 @@
 #!/usr/bin/env python3
 from setuptools import setup
+import sys
+
+if not sys.version_info[0] == 3:
+    sys.exit("Sorry, Cistern only supports Python 3.")
 
 setup(
     name="cistern",
-    version="0.1.3",
+    version="0.1.4",
     license="MIT",
     url="https://github.com/archangelic/cistern",
     description="Command line tool for downloading torrents from RSS feeds.",
     author="Michael Hancock",
     author_email="[email protected]",
     download_url=(
-        "https://github.com/archangelic/cistern/archive/v0.1.3.tar.gz"
+        "https://github.com/archangelic/cistern/archive/v0.1.4.tar.gz"
     ),
     install_requires=[
         'click',