Add --version option in option handler.

diceware.py

@@ -40,6 +40,10 @@ def handle_options(args):
         type=argparse.FileType('r'),
         help="Input wordlist. `-' will read from stdin.",
         )
+    parser.add_argument(
+        '--version', action='store_true',
+        help='output version information and exit.',
+        )
     parser.set_defaults(capitalize=True)
     args = parser.parse_args(args)
     return args

tests/test_diceware.py

@@ -157,6 +157,7 @@ class TestDicewareModule(object):
         assert options.capitalize is True
         assert options.specials == 0
         assert options.infile is None
+        assert options.version is False
 
     def test_handle_options_infile(self, tmpdir):
         # we can give an infile
@@ -167,6 +168,11 @@ class TestDicewareModule(object):
         assert options.infile is not None
         assert options.infile.read() == 'one\ntwo\n'
 
+    def test_handle_options_version(self):
+        # we can ask for version infos
+        options = handle_options(['--version', ])
+        assert options.version is True
+
     def test_main(self, capsys):
         # we can get a passphrase
         main([])  # call with default options in place