[LIBCLOUD-640] Add support for Softlayer DNS driver.

Closes #413

Signed-off-by: Tomaz Muraus <tomaz@apache.org>
Re-generate supported providers and methods table.
[LIBCLOUD-647] Fix ex_keyname argument handling in the create_node method of
the Softlayer driver.

Closes #416

Signed-off-by: Tomaz Muraus <tomaz@apache.org>
Updates CloudSigma DC list

Removes:
 * Las Vegas, NV
Adds:
 * San Jose, CA
 * Miami, FL

Closes #417

Signed-off-by: Tomaz Muraus <tomaz@apache.org>
Use new container based travis infrastructure.
Fix changelog - put entry under the correct section.