Replaces `with_*` loops with the new `loop` keyword.[1]

Note that with_dict => loop uses the dictsort filter as dict2items is
not available until Ansible 2.6.

[1] https://docs.ansible.com/ansible/2.7/porting_guides/porting_guide_2.5.html#migrating-from-with-x-to-loop

Replaces static includes with import_tasks (partially resolves StackStorm#190).

Replaces dynamic includes with include_tasks (resolves StackStorm#190).

include_tasks (introduced in Ansible 2.4) does not support ansible 1.x
style inline vars syntax (var=value) (since at least Ansible 2.4.1)[1].
If the syntax ever worked, removing support for it was announced in the
Ansible 2.7 Porting Guide[2]. So, this modifies include loops to be
include_tasks loops using the `vars` key instead of the inline syntax.

[1] ansible/ansible#32812
[2] https://docs.ansible.com/ansible/2.7/porting_guides/porting_guide_2.7.html#include-tasks-import-tasks-inline-variables

Dynamic includes (include_tasks) do not apply tags to internal tasks.[1]
Once we transition to 2.7, we can use `apply` on the `include_tasks`
module to specify the tags for included files.[2]

[1] https://docs.ansible.com/ansible/2.7/porting_guides/porting_guide_2.5.html#dynamic-includes-and-attribute-inheritance
[2] https://docs.ansible.com/ansible/2.7/modules/include_tasks_module.html

Bump the minimum ansible version for the remaining roles.

With 2.5, facts are now namespaced under ansible_facts.[1]
They are still accessible under the ansible_* vars, however that can be
disabled by setting `inject_facts_as_vars` to False. The default is True
in 2.5, but "is expected to be set to 'False' in a future release.
Migrating now means these roles and playbooks do not depend on this
setting being True.

[1] https://docs.ansible.com/ansible/2.7/porting_guides/porting_guide_2.5.html#ansible-fact-namespacing