cosalib/cli: drop unused --dump argument

It's been unused since it was introduced in ea00b56.

Author: bgilbert

src/cosalib/cli.py

@@ -147,9 +147,6 @@ def __init__(self, *args, **kwargs):
         self.add_argument(
             '--buildroot', env_var="BUILD_ROOT", default='builds',
             help='Build directory')
-        self.add_argument(
-            '--dump', default=False, action='store_true',
-            help='Dump the manfiest and exit')
         self.add_argument(
             '--schema', env_var="META_SCHEMA",
             default='/usr/lib/coreos-assembler/v1.json',

tests/test_cli.py

@@ -37,7 +37,7 @@ def test_build_cli_additional_args():
     Ensure that BuildCli contains the expected additional default args
     """
     parser = BuildCli()
-    expected = ['--build', '--buildroot', '--dump']
+    expected = ['--build', '--buildroot']
     for action in parser._actions:
         for expect in expected:
             if expect in action.option_strings: