Skip inactive environments while getting the project.

In case one wants to, there is new `--include-inactive` option.
Add initial Domains related commands.
Improve Domain List command.
Define the API structure for domains.
Add the List Command.
Fix the wildcard check.
New command for adding a domain.
Quick fix.
Initial version of the Delete Domain command.
Updated readme with updated install instructions regarding Drush.
Fix the Delete Domain command.
Get rid of the SSL Add command.
Better display of the domains.
Fix domain properties.
Remove unused lines.
Merge pull request #64 from nvahalik/master

Updated readme with updated install instructions regarding Drush.
Don't skip SSL check.
Merge pull request #62 from GuGuss/guguss-master

Additional command to list the domains attached to a project.
Merge pull request #66 from platformsh/add_ssl_check

Don't skip SSL check.
List lists all commands, not help.