add test for auth_request_url

tests/test_auth.py

@@ -0,0 +1,16 @@
+try:
+    from urllib.parse import urlparse, parse_qs
+except ImportError:
+     from urlparse import urlparse, parse_qs
+
+def test_auth_request_url(api):
+    url = api.auth_request_url()
+    parse = urlparse(url)
+    assert parse.path == '/oauth/authorize'
+    query = parse_qs(parse.query)
+    assert query['client_id'][0] == api.client_id
+    assert query['response_type'][0] == 'code'
+    assert query['redirect_uri'][0] == 'urn:ietf:wg:oauth:2.0:oob'
+    assert set(query['scope'][0].split()) == set(('read', 'write', 'follow'))
+
+