Add support for retries options in notifications

Nr of retries options added to Notifications plugin
in commit ee22c8b released in notification-1.12 July 2017.

Change-Id: I3271dfd68cd8d28024af952cda7500d438a2676e

jenkins_jobs/modules/notifications.py

@@ -41,9 +41,11 @@ def http_endpoint(registry, xml_parent, data):
     :arg str event: job events that trigger notifications: started,
         completed, finalized or all (default)
     :arg str url: URL of the endpoint
-    :arg str timeout: Timeout in milliseconds for sending notification
+    :arg int timeout: Timeout in milliseconds for sending notification
         request (30 seconds by default)
-    :arg str log: Number lines of log messages to send (0 by default).
+    :arg int retries: Nr of times to retry sending notification in case
+        sending notification fails. (0 by default)
+    :arg int log: Number lines of log messages to send (0 by default).
         Use -1 for all (use with caution).
 
     Example:
@@ -65,6 +67,7 @@ def http_endpoint(registry, xml_parent, data):
         ("", "protocol", "HTTP"),
         ("", "event", event, supported_events),
         ("timeout", "timeout", 30000),
+        ("retries", "retries", 0),
         ("url", "url", None),
         ("log", "loglines", 0),
     ]

tests/notifications/fixtures/http-endpoint001.xml

@@ -8,6 +8,7 @@
           <protocol>HTTP</protocol>
           <event>all</event>
           <timeout>30000</timeout>
+          <retries>0</retries>
           <url>http://example.com/jenkins_endpoint</url>
           <loglines>0</loglines>
         </com.tikal.hudson.plugins.notification.Endpoint>

tests/notifications/fixtures/http-endpoint002.xml

@@ -8,6 +8,7 @@
           <protocol>HTTP</protocol>
           <event>completed</event>
           <timeout>40000</timeout>
+          <retries>5</retries>
           <url>http://example.com/jenkins_endpoint</url>
           <loglines>-1</loglines>
         </com.tikal.hudson.plugins.notification.Endpoint>

tests/notifications/fixtures/http-endpoint002.yaml

@@ -5,3 +5,4 @@ notifications:
       event: completed
       timeout: 40000
       log: -1
+      retries: 5