title: django 1.10 csrf_token not creating hidden input field
body: <p>I have a form, but Django is not creating a hidden input like - </p>
  
  <pre><code>&lt;input type="hidden" name="csrfmiddlewaretoken" value="80NGejzAPl2aCbEEuyLqIT3ppMTJLilY"&gt;
  </code></pre>
  
  <p>If trying send a form I have 403 mistake, CSRF token missing or incorrect.</p>
  
  <p>This is my code:</p>
  
  <p>html    </p>
  
  <pre><code>&lt;form class="get-info" action="{% url 'callback:send_callback' %}" method="post"&gt;{% csrf_token %} ... &lt;/form&gt;
  </code></pre>
  
  <p>middleware</p>
  
  <pre><code>'django.middleware.csrf.CsrfViewMiddleware',
  </code></pre>
  
  <p>views.py</p>
  
  <pre><code>from django.core.mail import BadHeaderError, send_mail
  from django.http import HttpResponse, HttpResponseRedirect, request
  from django.shortcuts import render, render_to_response
  from django.template import RequestContext
  from django.template.context_processors import csrf
  from django.contrib import messages
  
  def callback(request):
      phone = request.POST.get('phone', None)
      lastpath = request.POST.get('lastpath', None)
      if validatePhone(phone):
          if sendMail(phone):
              messages.success(request, 'Мы скоро перезвоним Вам')
              return HttpResponseRedirect(lastpath)
          else:
              messages.error(request, 'Ошибка в отправке запроса. Попробуйте позже.')
              return HttpResponseRedirect(lastpath)
      else:
          messages.error(request, "Неверный формат номера телефона. Телефон нужно вводить в формате +99999999999")
          args = {}
          zzz = lastpath.render(RequestContext(request, args))
          return HttpResponse(zzz)
  </code></pre>
  
  <p>Callback url - </p>
  
  <pre><code>urlpatterns = [
      url(r'^callback/', views.callback, name='send_callback'),
  ]
  </code></pre>
  
  <p>Form rendering on the main page: </p>
  
  <pre><code>&lt;form class="get-info" action="/callback/callback/" method="post"&gt;
      &lt;input type="hidden" name="_subject" value="karpaty-perezvonite-mne"&gt;
      &lt;input id="callback" name="phone" type="tel" class="form-control"    placeholder="+ 380 ___-__-__"&gt;
      &lt;input type="text" class="form-control" placeholder="" name="lastpath" value="/" style="display: none"&gt;
      &lt;button type="submit" class="btn btn-default" value="Send"&gt;Отправить&lt;/button&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>I'm trying submit form to the main page - "/" and now have such mistake </p>
  
  <pre><code>UserWarning: A {% csrf_token %} was used in a template, but the context did not provide the value.  
  This is usually caused by not using RequestContext.
  </code></pre>
  
  <p>How can I fix it?</p>