Return 401 when getting an empty bearer token

For example:

Authorization: Bearer

The cause of the empty bearer also needs to be investigated

spec/swift/app_spec.rb

@@ -280,7 +280,6 @@ describe "App" do
     end
 
     context "not authorized" do
-
       describe "with no token" do
         it "says it's not authorized" do
           delete "/phil/food/aguacate"
@@ -290,6 +289,16 @@ describe "App" do
         end
       end
 
+      describe "with empty token" do
+        it "says it's not authorized" do
+          header "Authorization", "Bearer "
+          delete "/phil/food/aguacate"
+
+          last_response.status.must_equal 401
+          last_response.body.must_equal "Unauthorized"
+        end
+      end
+
       describe "with wrong token" do
         it "says it's not authorized" do
           header "Authorization", "Bearer wrongtoken"