subtests.docker_daemon: Adds tests for connection with certificate.

Tests generates certificates and sign them up with created CA certificate,
then test connect server and client part with different configurations.

Signed-off-by: Jiří Župka <jzupka@redhat.com>
I don't see problem in self.conts it safe some writing and is is more readable and command is possible write to one line. Thinks like conts, images, ..  should be placed in subtest directly. And I don't see any pylint complain about self.conts because it is class variable.
Please high light me line where is something about conts?
```pylint
I: 32, 0: Locally disabling C0103 (locally-disabled)
I: 32, 0: Locally disabling C0111 (locally-disabled)
I: 32, 0: Locally disabling R0904 (locally-disabled)
I: 73, 0: Locally disabling W0221 (locally-disabled)
C:  5, 0: Line too long (90/80) (line-too-long)
C:  8, 0: Line too long (85/80) (line-too-long)
C:  9, 0: Line too long (87/80) (line-too-long)
C: 11, 0: Line too long (85/80) (line-too-long)
C: 12, 0: Line too long (108/80) (line-too-long)
F: 21, 0: Unable to import 'autotest.client.shared' (import-error)
F: 22, 0: Unable to import 'dockertest.subtest' (import-error)
F: 23, 0: Unable to import 'dockertest.containers' (import-error)
F: 24, 0: Unable to import 'dockertest.dockercmd' (import-error)
F: 25, 0: Unable to import 'dockertest.images' (import-error)
F: 26, 0: Unable to import 'dockertest.config' (import-error)
F: 27, 0: Unable to import 'dockertest.xceptions' (import-error)
F: 28, 0: Unable to import 'dockertest' (import-error)
F: 29, 0: Unable to import 'dockertest' (import-error)
E: 58, 4: Use of super on an old style class (super-on-old-class)
W: 58,23: Redefining name 'subtest' from outer scope (line 28) (redefined-outer-name)
R: 58, 4: Too many arguments (8/5) (too-many-arguments)
E: 74, 4: Use of super on an old style class (super-on-old-class)
W:125,23: Redefining name 'subtest' from outer scope (line 28) (redefined-outer-name)
R:112, 0: Too few public methods (1/2) (too-few-public-methods)
W:170, 0: Class has no __init__ method (no-init)
E:182,42: Instance of 'DockerContainersCLISpec' has no 'subtest' member (no-member)
E:187,22: Instance of 'DockerContainersCLISpec' has no 'timeout' member (no-member)
E:189,33: Instance of 'DockerContainersCLISpec' has no 'verbose' member (no-member)
R:170, 0: Too few public methods (1/2) (too-few-public-methods)
W:193, 0: Class has no __init__ method (no-init)
W:232,20: Attribute 'remove_args' defined outside __init__ (attribute-defined-outside-init)
R:193, 0: Too few public methods (0/2) (too-few-public-methods)
W:197, 0: Class has no __init__ method (no-init)
R:197, 0: Too few public methods (0/2) (too-few-public-methods)
W:201, 0: Class has no __init__ method (no-init)
E:207, 4: Use of super on an old style class (super-on-old-class)
E:209,22: Instance of 'tls_base' has no 'config' member (no-member)
E:211,20: Instance of 'tls_base' has no 'config' member (no-member)
E:212,35: Instance of 'tls_base' has no 'config' member (no-member)
E:214,39: Instance of 'tls_base' has no 'parent_subtest' member (no-member)
E:215, 8: Instance of 'DockerContainersE' has no 'interface' member (no-member)
E:216, 8: Instance of 'DockerContainersE' has no 'interface' member (no-member)
E:219, 8: Instance of 'tls_base' has no 'sub_stuff' member (no-member)
E:220, 8: Instance of 'tls_base' has no 'sub_stuff' member (no-member)
E:221, 8: Instance of 'tls_base' has no 'sub_stuff' member (no-member)
E:222, 8: Instance of 'tls_base' has no 'sub_stuff' member (no-member)
E:225, 4: Use of super on an old style class (super-on-old-class)
E:228,12: Instance of 'tls_base' has no 'config' member (no-member)
E:229,32: Instance of 'tls_base' has no 'sub_stuff' member (no-member)
E:230,24: Instance of 'tls_base' has no 'sub_stuff' member (no-member)
W:234,23: Catching too general exception Exception (broad-except)
E:233,20: Instance of 'DockerContainersE' has no 'remove_by_name' member (no-member)
E:235,20: Instance of 'tls_base' has no 'logwarning' member (no-member)
E:238,11: Instance of 'tls_base' has no 'sub_stuff' member (no-member)
E:239,42: Instance of 'tls_base' has no 'sub_stuff' member (no-member)
E:254,34: Instance of 'tls_base' has no 'parent_subtest' member (no-member)
E:255,34: Instance of 'tls_base' has no 'tmpdir' member (no-member)
R:259, 4: Method could be a function (no-self-use)
R:272, 4: Method could be a function (no-self-use)
E:304,12: Instance of 'tls_base' has no 'logwarning' member (no-member)
W:308, 0: Class has no __init__ method (no-init)
E:310, 4: Use of super on an old style class (super-on-old-class)
E:317,17: Instance of 'tls_verify_all_base' has no 'tmpdir' member (no-member)
E:336, 8: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:340, 4: Use of super on an old style class (super-on-old-class)
E:344,35: Instance of 'tls_verify_all_base' has no 'config' member (no-member)
E:345,37: Instance of 'tls_verify_all_base' has no 'config' member (no-member)
E:346,33: Instance of 'tls_verify_all_base' has no 'config' member (no-member)
E:352, 8: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:354,11: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:355,12: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:355,43: Instance of 'DockerContainersE' has no 'get_unique_name' member (no-member)
E:356,12: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:356,48: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:360,12: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:362,12: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:362,48: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:365,50: Instance of 'tls_verify_all_base' has no 'config' member (no-member)
E:366,32: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:369, 8: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:372, 8: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:374, 4: Use of super on an old style class (super-on-old-class)
E:377,22: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
E:378,12: Instance of 'tls_verify_all_base' has no 'sub_stuff' member (no-member)
W:381, 0: Class has no __init__ method (no-init)
E:383, 4: Use of super on an old style class (super-on-old-class)
E:405,41: Instance of 'tls_verify_all_base_bad' has no 'config' member (no-member)
E:406,39: Instance of 'tls_verify_all_base_bad' has no 'config' member (no-member)
E:407,12: Instance of 'DockerContainersE' has no 'interface' member (no-member)
E:409,13: Instance of 'DockerContainersE' has no 'list_containers_with_name' member (no-member)
E:409,50: Instance of 'tls_verify_all_base_bad' has no 'sub_stuff' member (no-member)
E:411,12: Instance of 'tls_verify_all_base_bad' has no 'sub_stuff' member (no-member)
E:411,48: Instance of 'tls_verify_all_base_bad' has no 'sub_stuff' member (no-member)

```