Refactor rspec tests

Change-Id: I4721cacff86a88ff360b7a3ede45464ff44e684d
Deprecation of keystone_scheme,host,port params

Use deprecated parameters if any value is passed to preserve
proper backward compatibility.

Change-Id: I685b2430c06893dd3e80c4900e832024f0436ea8
Closes-bug: #1273442
Add ability to disable configuration of apache

Add configure_apache parameter to add the ability to disable
configuration of Apache vhost for Horizon.

- Move Apache configuration to horizon::wsgi::apache class.
- Move management of logdir resource to horizon::wsgi::apache class.

Change-Id: I5aeb577ce827e923ed01a73cca1bd79789f81eff
Closes-bug: #1190282