Edit Button not displaying on "quiz_detail.html"

{% extends "courses/layout.html" %}
{% load course_extras %}

{% block title %}{{ step.title }} | {{ step.course.title }} {{ block.super }}{% endblock %}

{% block breadcrumbs %}
    <li><a href="{% url 'courses:detail' pk=step.course.pk %}">{{ step.course.title }}</a></li>
{% endblock %}

{% block content %}
    <div class="row columns">
        <article>
            {{ block.super }}
            <h1>{{ step.title }}</h1>
            Quiz questions here
        </article>
        {% if user.is_authenticated %}
        <hr>
        <a href="{% url 'courses:edit_quiz' course_pk=step.course.pk quiz_pk=step.pk %}" class="button">Edit</a>
        {% endif %}
    </div>
{% endblock %}

from itertools import chain

from django.contrib import messages
from django.contrib.auth.decorators import login_required
from django.http import HttpResponseRedirect
from django.shortcuts import get_object_or_404, render

from . import forms
from . import models


def course_list(request):
    courses = models.Course.objects.all()
    return render(request, 'courses/course_list.html', {'courses': courses})


def course_detail(request, pk):
    course = get_object_or_404(models.Course, pk=pk)
    steps = sorted(chain(course.text_set.all(), course.quiz_set.all()),
                  key=lambda step: step.order)
    return render(request, 'courses/course_detail.html', {
            'course': course,
            'steps': steps,
        })


def text_detail(request, course_pk, step_pk):
    step = get_object_or_404(models.Text, course_id=course_pk, pk=step_pk)
    return render(request, 'courses/step_detail.html', {'step': step})


def quiz_detail(request, course_pk, step_pk):
    step = get_object_or_404(models.Quiz, course_id=course_pk, pk=step_pk)
    return render(request, 'courses/step_detail.html', {'step': step})


@login_required
def quiz_create(request, course_pk):
    course = get_object_or_404(models.Course, pk=course_pk)
    form = forms.QuizForm()

    if request.method == 'POST':
        form = forms.QuizForm(request.POST)
        if form.is_valid():
            quiz = form.save(commit=False)
            quiz.course = course
            quiz.save()
            messages.add_message(request, 
                                 messages.SUCCESS, 
                                 "Quiz added!"
                                )
            return HttpResponseRedirect(quiz.get_absolute_url())
    return render(request, 'courses/quiz_form.html', {'form': form, 'course': course})


@login_required
def quiz_edit(request, course_pk, quiz_pk):
    quiz = get_object_or_404(models.Quiz, pk=quiz_pk, course_id=course_pk)
    form = forms.QuizForm(instance=quiz)

    if request.method == 'POST':
        form = forms.QuizForm(instance=quiz, data=request.POST)
        if form.is_valid():
            form.save()
            messages.success(request, "Updated {}".format(form.cleaned_data['title']))
            return HttpResponseRedirect(quiz.get_absolute_url())
    return render(request, 'courses/quiz_form.html', {'form': form, 'course': quiz.course})

from django.conf.urls import url

from . import views

urlpatterns = [
    url(r'^$', views.course_list, name='list'),
    url(r'(?P<course_pk>\d+)/t(?P<step_pk>\d+)/$', views.text_detail, name='text'),
    url(r'(?P<course_pk>\d+)/q(?P<step_pk>\d+)/$', views.quiz_detail, name='quiz'),
    url(r'(?P<course_pk>\d+)/create_quiz/$', views.quiz_create, name='create_quiz'),
    url(r'(?P<course_pk>\d+)/edit_quiz/(?P<quiz_pk>\d+)/$', views.quiz_edit, name='edit_quiz'),
    url(r'(?P<pk>\d+)/$', views.course_detail, name='detail'),
]