Feature/added ipc flag

[sachinkum0009]

• Introduced a new IPC class that extends RockerExtension to handle IPC namespace options.
• Implemented get_name to return the 'ipc' identifier.
• Added get_docker_args method to generate Docker IPC arguments based on CLI input.
• Included a get_preamble method that returns an empty string as no preamble is needed.

This PR enables the use of IPC-related Docker arguments in Rocker configurations and should close the issue #241.

[tfoote]

Thanks for the contribution, I thought that this was going to be more complicated. Overall it looks good. I have a few stylistic changes and a request for adding a full link for the options documentation which is oddly hard to get to directly.

Can you please add a basic test too to make sure that it gets passed through correctly and we keep coverage high. You can use the network test as a good example:

rocker/test/test_extension.py

Lines 117 to 147 in 73ab0d6

	class NetworkExtensionTest(unittest.TestCase):
	def setUp(self):
	# Work around interference between empy Interpreter
	# stdout proxy and test runner. empy installs a proxy on stdout
	# to be able to capture the information.
	# And the test runner creates a new stdout object for each test.
	# This breaks empy as it assumes that the proxy has persistent
	# between instances of the Interpreter class
	# empy will error with the exception
	# "em.Error: interpreter stdout proxy lost"
	em.Interpreter._wasProxyInstalled = False
	@pytest.mark.docker
	def test_network_extension(self):
	plugins = list_plugins()
	network_plugin = plugins['network']
	self.assertEqual(network_plugin.get_name(), 'network')
	p = network_plugin()
	self.assertTrue(plugin_load_parser_correctly(network_plugin))
	mock_cliargs = {'network': 'none'}
	self.assertEqual(p.get_snippet(mock_cliargs), '')
	self.assertEqual(p.get_preamble(mock_cliargs), '')
	args = p.get_docker_args(mock_cliargs)
	self.assertTrue('--network none' in args)
	mock_cliargs = {'network': 'host'}
	args = p.get_docker_args(mock_cliargs)
	self.assertTrue('--network host' in args)

[tfoote]

Thanks for the cleanup and adding a test. This is great to add as a feature.