PERF: Store EmailLog#reply_key as uuid data type.

spec/models/email_log_spec.rb

@@ -101,19 +101,20 @@ describe EmailLog do
     end
   end
 
-  describe '#bounce_key' do
-    it 'should format the bounce key correctly' do
-      bounce_key = SecureRandom.hex
-      email_log = Fabricate(:email_log, user: user, bounce_key: bounce_key)
+  %w{reply_key bounce_key}.each do |key|
+    describe "##{key}" do
+      it "should format the #{key} correctly" do
+        hex = SecureRandom.hex
+        email_log = Fabricate(:email_log, user: user, "#{key}": hex)
 
-      raw_bounce_key = EmailLog.where(id: email_log.id)
-        .pluck("bounce_key::text")
-        .first
+        raw_key = EmailLog.where(id: email_log.id)
+          .pluck("#{key}::text")
+          .first
 
-      expect(raw_bounce_key).to_not eq(bounce_key)
-      expect(raw_bounce_key.delete('-')).to eq(bounce_key)
-      expect(EmailLog.find(email_log.id).bounce_key).to eq(bounce_key)
+        expect(raw_key).to_not eq(hex)
+        expect(raw_key.delete('-')).to eq(hex)
+        expect(EmailLog.find(email_log.id).send(key)).to eq(hex)
+      end
     end
   end
-
 end