Clears cache around examples

for specs testing cache

spec/system/consumer/caching/darkswarm_caching_spec.rb

@@ -19,6 +19,11 @@ describe "Darkswarm data caching", caching: true do
   }
   let(:exchange) { order_cycle.exchanges.outgoing.where(receiver_id: distributor.id).first }
 
+  around do |example|
+    Rails.cache.clear
+    example.run
+  end
+
   before do
     exchange.variants << product.variants.first
   end

spec/system/consumer/caching/shops_caching_spec.rb

@@ -13,6 +13,11 @@ describe "Shops caching", caching: true do
     create(:open_order_cycle, distributors: [distributor], coordinator: distributor)
   }
 
+  around do |example|
+    Rails.cache.clear
+    example.run
+  end
+
   describe "caching enterprises AMS data" do
     it "caches data for all enterprises, with the provided options" do
       visit shops_path