todolists: Add test for templatetags

Test a simple case of the todolist_details_link template tag

todolists/tests/test_templatetags_todolists.py

+from django.contrib.auth.models import User
+from django.test import TestCase
+
+
+from main.models import Package
+from todolists.models import Todolist, TodolistPackage
+from todolists.templatetags.todolists import todopkg_details_link
+
+
+class TestTodolist(TestCase):
+    fixtures = ['main/fixtures/arches.json', 'main/fixtures/repos.json',
+                'main/fixtures/package.json']
+
+    def setUp(self):
+        self.user = User.objects.create(username="joeuser", first_name="Joe",
+                                        last_name="User", email="user1@example.com")
+        self.todolist = Todolist.objects.create(name='Boost rebuild',
+                                                description='Boost 1.66 rebuid',
+                                                creator=self.user,
+                                                raw='linux')
+
+    def test_details_link(self):
+        pkg = Package.objects.first()
+        todopkg = TodolistPackage.objects.create(pkg=pkg, pkgname=pkg.pkgname,
+                                                 pkgbase=pkg.pkgbase, arch=pkg.arch,
+                                                 repo=pkg.repo, user=self.user,
+                                                 todolist=self.todolist)
+        link = todopkg_details_link(todopkg)
+        self.assertIn('View package details for {}'.format(todopkg.pkg.pkgname), link)