Failing Spec for button - ruby-on-rails

Question

So I recently took on a project upgrading a Ruby 1.9.3 / Rails 3.2 application to Ruby 2 / Rails 4.0.2. All seems to be well, but I have a failing spec. I'm trying to test that a button is working at the bottom of the page for a "suggestions" box.
Failure message is:
Failures:
1) StaticPages Scheduler Page after authenticating filling in the suggestion form after submitting the form should send an email request with the form contents
Failure/Error: click_button("suggestion-button")
ActionController::UnknownFormat:
ActionController::UnknownFormat
# ./app/controllers/static_pages_controller.rb:39:in `suggestion'
# ./spec/features/static_pages_spec.rb:93:in `block (6 levels) in <top (required)>'
Spec reads:
context "after submitting the form" do
before(:each) do
click_button("suggestion-button")
end
Controller reads:
def suggestion
if user_signed_in?
user = current_user.email
else
user = "< not logged in >"
end
if params[:suggestion]
ContactMailer.suggestion_email(params[:suggestion], params[:pathname], user).deliver!
end
respond_to do |format|
format.json { render json: params[:suggestion] }
end
end
The source for the button on the page is:
<button type="submit" class="btn" id="suggestion-button">
Tell Us!
</button>
</form>
<script>
// After form submission, gray out and disable the form
$(document).ready(function(){
$("#footer-suggestion-form").bind("ajax:complete", function(event, xhr, status){
console.log($("#footer-suggestion-form input"));
$("#footer-suggestion-form input").attr("disabled","disabled");
$("#footer-suggestion-form button").attr("disabled","disabled").html("Thanks!");
console.log("did it!");
});
$("#suggestion-pathname").val(location.pathname);
});
</script>
Is it because it's an AJAX form? Or just a test that worked in Rails 3.2 but no longer works in 4 because of some change? I appreciate any help, I am truly lost.
I did try using :js => true in the spec and downloading the capybara-webkit gem, but when I try to run the spec it gets to that test and then just hangs there waiting for something to happen that never does.
EDIT: Progress. Now it gets to that test, sits for a big, and then fails with
1) StaticPages Scheduler Page after authenticating filling in the suggestion form after submitting the form should send an email request with the form contents
Failure/Error: before { visit scheduler_path }
RuntimeError:
Rack application timed out during boot
./spec/features/static_pages_spec.rb:31:in `block (3 levels) in