adds spec for humanize document type helper [#500]

spec/helpers/admin_helper_spec.rb

@@ -0,0 +1,13 @@
+require 'rails_helper'
+
+describe AdminHelper do
+
+  describe '#humanize_document_type' do
+    it "should return a humanized document type" do
+      expect(humanize_document_type("1")).to eq "Spanish ID"
+      expect(humanize_document_type("2")).to eq "Passport"
+      expect(humanize_document_type("3")).to eq "Residence card"
+    end
+  end
+
+end