Remove misleading authorization error message in cert-request with --add

https://fedorahosted.org/freeipa/ticket/4540

Reviewed-By: Martin Kosek <mkosek@redhat.com>
Fix example usage in ipa man page.

https://fedorahosted.org/freeipa/ticket/4587

Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
tests: Use PEP8-compliant setup/teardown method names

The setUp/dearDown names are used unittest, but there is no reason
to use them in non-unittest test cases.
Nose supports both styles (but mixing them can cause trouble when
calling super()'s methods).
Pytest only supports the new ones.
tests: Add configuration for pytest

By default, pytest considers test classes only if they're named
'Test*'; Nose also allows 'test_*'.
Configure pytest to allow the non-pep8 names as well.
ipatests.util.ClassChecker: Raise AttributeError in get_subcls

Pytest considers NotImplementedError on attribute access an error.
test_automount_plugin: Fix test ordering

Nose ran the `test_a_*` and `test_a2_*` tests in opposite order
than the source suggested. Fix this.
Use setup_class/teardown_class in Declarative tests

Pytest will consider each Declarative test individually, running
setup/teardown for each one.
Move the setup and teardown to the class level.