Add Sentinel .Ping(), .Set(), .Monitor() and .Delete()

sentinel.go

@@ -130,6 +130,14 @@ func (c *SentinelClient) pubSub() *PubSub {
 	return pubsub
 }
 
+// Ping is used to test if a connection is still alive, or to
+// measure latency.
+func (c *SentinelClient) Ping() *StringCmd {
+	cmd := NewStringCmd("ping")
+	c.Process(cmd)
+	return cmd
+}
+
 // Subscribe subscribes the client to the specified channels.
 // Channels can be omitted to create empty subscription.
 func (c *SentinelClient) Subscribe(channels ...string) *PubSub {
@@ -219,6 +227,35 @@ func (c *SentinelClient) CkQuorum(name string) *StringCmd {
 	return cmd
 }
 
+// Monitor tells the Sentinel to start monitoring a new master with the specified
+// name, ip, port, and quorum. It is identical to the sentinel monitor configuration
+// directive in sentinel.conf configuration file, with the difference that you can't
+// use an hostname in as ip, but you need to provide an IPv4 or IPv6 address.
+func (c *SentinelClient) Monitor(name, ip, port, quorum string) *StringCmd {
+	cmd := NewStringCmd("sentinel", "monitor", name, ip, port, quorum)
+	c.Process(cmd)
+	return cmd
+}
+
+// Set is used in order to change configuration parameters of a specific master.
+// Multiple option / value pairs can be specified (or none at all). All the 
+// configuration parameters that can be configured via sentinel.conf are also
+// configurable using the SET command.
+func (c *SentinelClient) Set(name, option, value string) *StringCmd {
+	cmd := NewStringCmd("sentinel", "set", name, option, value)
+	c.Process(cmd)
+	return cmd
+}
+
+// Remove is used in order to remove the specified master: the master will no
+// longer be monitored, and will totally be removed from the internal state of
+// the Sentinel, so it will no longer listed by SENTINEL masters and so forth.
+func (c *SentinelClient) Remove(name string) *StringCmd {
+	cmd := NewStringCmd("sentinel", "remove", name)
+	c.Process(cmd)
+	return cmd
+}
+
 type sentinelFailover struct {
 	sentinelAddrs []string