Use python abc in DeletableResource class

Fix pylint error about NotImplemented raised instead of
NotImplementedError.

Use the abc class instead of NotImplementedError.

Partial-Bug: #1346797

Change-Id: I50df1edf5c6b5c7a5c385a6389da97ffffea4d07
Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>
Fix "NotFound" error in _clear_stacks()

_clear_stacks() will raise "NotFound" exception if stack was
deleted before wait its status. This patch adds a try block
to fix the problem.

Change-Id: I29d4e443e5f355dbba188ccebe930f9401f3ccea
Closes-Bug: #1355666
Migrate test_minimun_basic to tempest client

Migrate the test and along with it migrate all the shared
functions used by the tests from OfficialClienTest to
ScenarioTest:
- functions related to sync and async cleanup
- create_(keypair|server|volume|sec_group|loginable_rules)
- get_remote_client

Partially implements: bp:tempest-client-scenarios
Change-Id: Idb4a1487d48af24ebcee8e7a78822b2858c1e90b
Add glance tag to test_server_actions

Closes-bug #1289499

Change-Id: I96a778c10883d91591bb8afb26cc94445f59b2fc
Merge "Use python abc in DeletableResource class"
Merge "Fix "NotFound" error in _clear_stacks()"
Merge "Add glance tag to test_server_actions"
Merge "Migrate test_minimun_basic to tempest client"
Merge branch 'master' of https://github.com/openstack/tempest