Python 2 is not supported anymore

Fixes issue bulletmark#11.

.gitignore

@@ -1 +1,2 @@
+venv/
 README.html

Makefile

@@ -23,7 +23,7 @@ $(DOC): $(SRC)
 
 check:
 	flake8 $(PROG)
-	vermin -i -q $(PROG)
+	vermin --no-tips -i -q $(PROG)
 
 install::
 	install -CD $(PROG) ~/bin

README.md

@@ -14,11 +14,11 @@ EDID.
 
 ## Installation
 
-Requires python smbus module and edid-decode utility.
+Requires python3 smbus module, and edid-decode utility.
 
 Install these prerequisites on Debian/Ubuntu:
 
-    sudo apt-get install python-smbus edid-decode
+    sudo apt-get install python3-smbus edid-decode
 
 Or, install these prerequisites on Arch:
 
@@ -29,7 +29,8 @@ Get this source code:
     git clone https://github.com/bulletmark/edid-rw
     cd edid-rw
 
-This utility should run using python version 2.5+, or 3+.
+This utility should run using Python version 3.2+. It does not work with
+Python 2.
 
 ## Usage
 

edid-rw

@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 '''
 Program to read or write Extended Display Identification Data (EDID) to
 a digital display. Default action is to READ binary EDID data from
@@ -104,8 +104,9 @@ def main():
             if actsum != calsum:
                 if args.fix:
                     edid[x - 1] = calsum
-                    sys.exit('%s checksum 0x%02x was BAD, rewrote it to '
-                            '0x%02x.' % (blkname(b), actsum, calsum))
+                    sys.stderr.write(
+                            '%s checksum 0x%02x was BAD, rewrote it to '
+                            '0x%02x.\n' % (blkname(b), actsum, calsum))
                 else:
                     sys.exit('ERROR: %s checksum 0x%02x is BAD, should be '
                             '0x%02x.' % (blkname(b), actsum, calsum))