Add rspec:install to application template

Have the application template run 'generate rspec:install' and
insert "require 'rspec/autorun'" into the spec/spec_helper.rb file
so the application is ready for the user to test any customizations.

HYDRASIR-81 #close
Add question prompt for RSpec in application template

Use a prompt to allow the user to choose whether or not to include
support for spec tests in their custom code.

HYDRASIR-81 #close
Merge pull request #406 from projecthydra/feature/HYDRASIR-81-rspec-install-in-application-template

Add rspec:install to application template