Merge pull request #5 from safchain/service_instance

Add async start of the netns_command script
Small change to include statements

Change-Id: I6fb9554589d4243ebdf488f660069471a743c730
Simplify the dependencies to the namespace_manager so that it is easier to build an unit test

Change-Id: Ib5b108e493e712a875329ba4f4dfca98f1f0b7c9
Add unit test for the NamespaceManager class

Change-Id: Ia0497ae12983eaf4d4beea8ff17a29031dab3c52
Make sure that service_instance_test can still execute

Change-Id: I6eb8a656cf37c5337c14e6ecaca16c84b9b62419
Introduce NamespaceSate class

Change-Id: Ice600aab70667d869c2c983a902464a512cf4897