Fix typo

“ should be ".

README.md

diff --git a/README.md b/README.md
index ddfe795..55d3a8d 100644
--- a/README.md
+++ b/README.md
@@ -301,7 +301,7 @@
 * `logrus/formatters/logstash.LogstashFormatter`. Logs fields as [Logstash](http://logstash.net) Events.
 
     ```go
-      logrus.SetFormatter(&logstash.LogstashFormatter{Type: “application_name"})
+      logrus.SetFormatter(&logstash.LogstashFormatter{Type: "application_name"})
     ```
 
 Third party logging formatters: