Adds support for host definition by a environment variables of the
following form:
ROLE_<keyword>_envX, where X is the number of the environment
for which host referenced by a role <keyword> should be defined.
Adds a required_extra_roles attribute to the IntegrationTest class,
which can test developer use to specify the extra roles that this
particular test requires. If not all required extra roles are
available, the test will be skipped.
All extra (and static) roles are accessible to the IntegrationTests
via the host_by_role method, which returns a host of given role.
Part of: https://fedorahosted.org/freeipa/ticket/3833
Integration tests are configured via environment variables.
Add a framework for parsing these variables and storing them
in easy-to-use objects.
Add an `ipa-test-config` executable that loads the configuration
and prints out variables needed in shell scripts.
Part of the work for https://fedorahosted.org/freeipa/ticket/3621
