added birth institution record creation logic with a corresponding creation of an institution-person link, and associated testing 
some refactorings (and spelling corrections) based on feedback to pull request: decomposition of a test example and simplification of a method 
combining the formulation of a birth address record with an institution record
creating birth institution record #2785
added #address_empty? and #institution_empty? to aid birth institution address record creation #2785
added institution association to the person model
updated the pregnancy visit specs and fixtures to represent combining institution with birth address record creation
added missing data export identifier to maps #3045
updated and modified testing to account for data export identifier map changes
added testing to the PV low I ODE to confirm the proper creation of Institution and Birth Address records
added testing for using #process_institution as standalone, added #finalize_institution with testing #2785
added institution creation to birth ODE, with testing and fixtures #2785
added belongs_to relationship of response set to institution
added #get_birth_address and inserted it into workflow; ensured institution and associated records are not created if the institute is blank
added capability of #process_institution to look-up previous institution records prior to making a new one, refactored testing based on feedback
changed magic number to a constant
added #blank? to Address model
added #blank? to Institution model
wrapped up Institution and Birth Address record creation in transactions; made the institute type parameter optional with a default value of 'other'
added response_set parameter to #process_institution