test spawn

spawn.html

 {% extends "templates/spawn.html" %}
 
 {% block heading %}
+<p>Number of GPUs: {{ n_gpus }}</p>
 <label for="gpus">GPUs</label>
 <input class="form-control input-lg" type="range" name="gpus" value="{{ n_gpus }}" min="0" max="4" oninput="this.nextElementSibling.value = this.value"/>
 <output>{{ n_gpus }}</output>