Simplify poll stats test

Adding the option to assign a poll to a poll recount factory meant we
didn't need to create so much data.

Also note we're removing the `create(:poll_voter, origin: "booth")`
code, since it isn't used in the stats calculations.

spec/factories/polls.rb

@@ -88,7 +88,12 @@ FactoryBot.define do
     poll
     association :user, :level_two
     association :officer, factory: :poll_officer
+    from_web
+
+    trait :from_web do
       origin "web"
+      token SecureRandom.hex(32)
+    end
 
     trait :from_booth do
       origin "booth"
@@ -129,6 +134,16 @@ FactoryBot.define do
   factory :poll_recount, class: "Poll::Recount" do
     association :author, factory: :user
     origin "web"
+
+    trait :from_booth do
+      origin "booth"
+
+      transient { poll nil }
+
+      booth_assignment do
+        association :poll_booth_assignment, poll: poll
+      end
+    end
   end
 
   factory :officing_residence, class: "Officing::Residence" do

spec/models/poll/stats_spec.rb

@@ -2,16 +2,15 @@ require "rails_helper"
 
 describe Poll::Stats do
 
-  describe "Calculate stats" do
-    it "Generate the correct stats" do
+  describe "#generate" do
+    it "generates the correct stats" do
       poll = create(:poll)
-      booth = create(:poll_booth)
-      booth_assignment = create(:poll_booth_assignment, poll: poll, booth: booth)
-      create(:poll_voter, poll: poll, origin: "web")
-      3.times {create(:poll_voter, poll: poll, origin: "booth")}
-      create(:poll_voter, poll: poll)
-      create(:poll_recount, origin: "booth", white_amount: 1, null_amount: 0, total_amount: 2, booth_assignment_id: booth_assignment.id)
-      stats = described_class.new(poll).generate
+      2.times { create(:poll_voter, :from_web, poll: poll) }
+      3.times { create(:poll_voter, :from_booth, poll: poll) }
+      create(:poll_recount, :from_booth, poll: poll,
+             white_amount: 1, null_amount: 0, total_amount: 2)
+
+      stats = Poll::Stats.new(poll).generate
 
       expect(stats[:total_participants]).to eq(5)
       expect(stats[:total_participants_web]).to eq(2)