Ansible 2.11 does not like to have empty dependencies. It will fail to
install the collection with "'NoneType' object has no attribute 'items'"
error. The empty dependencies have been removed.
The requirements for ansible in requirements.txt have been removed also.
Fixes#571 (error installing freeipa-ansible_freeipa-0.3.6.tar.gz)
dependencoies may not be an empty dict like in the past, but it may also not
be missing. It simply needs to be empty.
Fixes#146 (ansible-freeipa collection not installable by 2.9 ansible-galaxy collection install)
