Make spec_driver_handles_share_servers required

This change makes the extra spec "spec_driver_handles_share_servers"
required for the type-create command in the Manila Client as opposed 
to being listed as an optional argument that was in fact required. I
had to remove a no longer valid test case in the unit test suite, 
but it was done because instead of throwing an exception, the 
argparser will just exit(2).

Change-Id: I0dc58cdfe10493a8eb736fa1bd0cd196bb0f5c05
Closes-Bug: #1484156

manilaclient/tests/unit/v1/test_shell.py

@@ -497,13 +497,6 @@ class ShellTest(test_utils.TestCase):
         cliutils.print_list.assert_called_once_with(
             mock.ANY, ['ID', 'Name', 'all_extra_specs'], mock.ANY)
 
-    def test_type_create_without_required_extra_spec(self):
-        self.assertRaises(
-            exceptions.CommandError,
-            self.run_command,
-            'type-create test',
-        )
-
     @ddt.data('fake', 'FFFalse', 'trueee')
     def test_type_create_invalid_extra_spec(self, extra_spec):
         self.assertRaises(

manilaclient/v1/shell.py

@@ -1838,10 +1838,9 @@ def do_extra_specs_list(cs, args):
 @cliutils.arg(
     'spec_driver_handles_share_servers',
     metavar='<spec_driver_handles_share_servers>',
-    default='',
-    nargs='?',
+    type=str,
     help="Required extra specification. "
-         "Valid values 'true'/'1' and 'false'/'0'")
+         "Valid values are 'true'/'1' and 'false'/'0'")
 @cliutils.arg(
     '--is_public',
     '--is-public',