use exponential back off func from realis lib (#39)

* use exponential back off func from realis lib

* remove exponential backoffs from monitors

* dont compare for retry errors

examples/client.go

@@ -22,10 +22,11 @@ import (
 
 	"time"
 
+	"strings"
+
 	"github.com/paypal/gorealis"
 	"github.com/paypal/gorealis/gen-go/apache/aurora"
 	"github.com/paypal/gorealis/response"
-	"strings"
 )
 
 var cmd, executor, url, clustersConfig, clusterName, updateId, username, password, zkUrl, hostList string

examples/clusters.json

@@ -5,4 +5,4 @@
   "auth_mechanism": "UNAUTHENTICATED",
   "slave_run_directory": "latest",
   "slave_root": "/var/lib/mesos"
-}]
+}]