require ontology-united

This gem should allow us to write ontologies
for testing purposes in a small dsl.
adjust spec helper for ontology testing dsl

Add a more generalized helper method to get a version
for a file (needed for ontology-united interaction).

Include the Convenience module for ontology-united
interaction.
add a spec for referenced ontologies

This utilizes the testing ontologies DSL
(provided by the ontology-united).
Merge branch 'staging' into 786-dsl_for_test_ontologies

Conflicts:
	spec/spec_helper.rb
Merge pull request #875 from ontohub/786-dsl_for_test_ontologies

786 dsl for test ontologies