Add extra-apt-sources via Self Service

• updated POST /:user/test/submit to accept the extra_apt_sources parameter for the test object in self_service.rb
• updated POST /:user/retry/:run_id for the new job to have same values of extra_apt_sources of original_job in self-service.rb.
• updated get_same_pending_jobs function in self_service.rb to consider values of extra_apt_sources as well.
• added new textfield for Extra APT Sources in self_service_test.erb.
• added row to display Extra APT Sources in retry.erb.
• added/updated tests in self_service_spec.rb for above.