Extend the Hound `find_element` function

This would be nice:

```ex
def find_element(:test, view_module, retries \\ 5) do
  {:safe, test_selector} = view_module.test()
  find_element(:xpath, ~s|//*[@#{test_selector}]|, retries)
end

find_element(:test, MyModule)
```

But this :(

```
** (CompileError) lib/test_selector/test_helpers.ex:1: imported Hound.Helpers.Page.find_element/2 conflicts with local function
```