Update requirements for example

Author: synw

example/requirements.txt

@@ -1,8 +1,7 @@
-Django==1.11.3
+Django<2
 django-filter==1.0.4
 django-filters==0.2.1
 django-graphql-utils==0.1.2
-django-rest-framework==0.1.0
 django-seed==0.1.7
 djangorestframework==3.6.3
 Faker==0.7.18
@@ -11,7 +10,6 @@ graphene-django==1.3
 graphql-core==1.1
 graphql-relay==0.4.5
 iso8601==0.1.11
-pkg-resources==0.0.0
 promise==2.0.2
 python-dateutil==2.6.1
 pytz==2017.2