Restart the node according to the schedule.

The scheduled restart data structures are now independent of those
used by the normal restarts. This would be fixed in subsequent
commits.
Add the behave tests, that cover the POST /restart (but not DELETE).

tests/test_api.py

@@ -3,6 +3,7 @@ import json
 import psycopg2
 import unittest
 
+import dateutil.parser
 from mock import Mock, patch
 from patroni.api import RestApiHandler, RestApiServer
 from patroni.dcs import ClusterConfig, Member
@@ -66,7 +67,7 @@ class MockPatroni(object):
     tags = {}
     version = '0.00'
     noloadbalance = Mock(return_value=False)
-    scheduled_restart = {'schedule': '2016-08-29 12:45TZ+1'}
+    scheduled_restart = {'schedule': dateutil.parser.parse('2016-08-29 12:45TZ+1')}
 
     @staticmethod
     def sighup_handler():