Fix version comparisons (#22)
String comparisons don't work properly for Python versions because for
example "3.10.0" < "3.8.0". Use sys.hexversion instead.
diff --git a/setup.py b/setup.py
index 57e9428..c390c06 100755
--- a/setup.py
+++ b/setup.py
@@ -43,7 +43,7 @@
# This is used since python_requires field is not recognized with
# pip version 9.0.0 and earlier
-if sys.version < '2.7':
+if sys.hexversion < 0x020700f0:
print('%s requires Python 2.7 or later.' % _PACKAGE_NAME, file=sys.stderr)
sys.exit(1)