feat(types de champ): add EPCI champ

spec/models/champs/epci_champ_spec.rb

@@ -0,0 +1,23 @@
+describe Champs::EpciChamp, type: :model do
+  let(:memory_store) { ActiveSupport::Cache.lookup_store(:memory_store) }
+
+  before do
+    allow(Rails).to receive(:cache).and_return(memory_store)
+    Rails.cache.clear
+  end
+
+  let(:champ) { described_class.new }
+
+  describe 'value', vcr: { cassette_name: 'api_geo_epcis' } do
+    it 'with departement and code' do
+      champ.code_departement = '01'
+      champ.value = '200042935'
+      expect(champ.external_id).to eq('200042935')
+      expect(champ.value).to eq('CA Haut - Bugey Agglomération')
+      expect(champ.selected).to eq('200042935')
+      expect(champ.code).to eq('200042935')
+      expect(champ.departement?).to be_truthy
+      expect(champ.to_s).to eq('CA Haut - Bugey Agglomération')
+    end
+  end
+end