Update donation link

https://otwarchive.atlassian.net/browse/AO3-6621

app/views/home/donate.html.erb

@@ -8,5 +8,5 @@
   <h3><%= ts('Donating Financially') %></h3>
   <p><%= ts("The AO3 has ongoing running costs - electricity for the servers and bandwidth so you can reach them - 
 and one-off costs such as buying new servers as the number of users and works increases. 
-Any <a href=\"https://otw.cividesk.com/civicrm/index.php?q=civicrm/contribute/transact&reset=1&id=17\">donation to the OTW</a> is a big help. (Don't worry, we'll never connect your AO3 username and your financial information.)").html_safe %></p>
+Any <a href=\"https://donate.transformativeworks.org/otwgive\">donation to the OTW</a> is a big help. (Don't worry, we'll never connect your AO3 username and your financial information.)").html_safe %></p>
 </div>

features/other_a/homepage.feature

@@ -24,3 +24,4 @@ Feature: Various things on the homepage
     And I follow "Donations"
   Then I should see "There are two main ways to support the AO3 - donating your time or money"
     And I should see the page title "Donate or Volunteer"
+    And I should see a link "donation to the OTW" to "https://donate.transformativeworks.org/otwgive"

features/step_definitions/generic_steps.rb

@@ -240,6 +240,10 @@ def assure_xpath_not_present(tag, attribute, value, selector)
   page.body.should =~ /#{Regexp.escape(text)}/m
 end
 
+Then "I should see a link {string} to {string}" do |text, href|
+  expect(page).to have_link(text, href: href)
+end
+
 Then /^I should not see a link "([^\"]*)"$/ do |name|
   text = name + "</a>"
   page.body.should_not =~ /#{Regexp.escape(text)}/m