add database cleaner

add factory girl
fix tests
rename dossier_pdf into piece_jointe
rename ref_piece_jointe into content

spec/models/dossier_spec.rb

@@ -0,0 +1,22 @@
+require 'spec_helper'
+
+describe Dossier do
+  let(:dossier) { create(:dossier, :with_entreprise) }
+
+  let(:entreprise) { dossier.entreprise }
+  let(:etablissement) { dossier.etablissement }
+
+  subject { dossier }
+
+  describe '#siren' do
+    it 'returns entreprise siren' do
+      expect(subject.siren).to eq(entreprise.siren)
+    end
+  end
+
+  describe '#siret' do
+    it 'returns etablissement siret' do
+      expect(subject.siret).to eq(etablissement.siret)
+    end
+  end
+end