Rspec-rails img src and timestamps

There is probably an easy solution to this but I am new to rails and
rspec and after searching I cannot seem to find an answer. When I try
the following code:

response.should have_selector("#logo", :src => “/images/logo.jpg”)

it fails because rails appends a ? and timestamp to the end of the
image name. If I put the full name it passes.

response.should have_selector("#logo", :src => “/images/logo.jpg?
1243997048”)