Use Relative pathes for ora and xqueue auth.json and env.json
Merge pull request #162 from edx/jbau/ora-xqueue-relative-env-json-path

Use Relative pathes for ora and xqueue auth.json and env.json
Use ansible facts instead of facter.

The ansible_processor field provides a list of all hyperthreaded cores. Using
Jinja we can just get the number of cores on the machine by running length on
this list.
Add missing length calculation.
Merge pull request #168 from edx/feanil/remove_facter

Use ansible facts instead of facter.
Make the condition on migrate_db a bit safer for using in var_prompt
Merge pull request #169 from edx/jbau/safer_migrate_db

Make the condition on migrate_db a bit safer for using in var_prompt