Update version to v1.1.1

Change-Id: I9d8f8c665764fc0b922368ba1290d105fea5cc80

Author: skriptble

README.md

@@ -31,7 +31,7 @@ The MongoDB supported driver for Go.
 The recommended way to get started using the MongoDB Go driver is by using `dep` to install the dependency in your project.
 
 ```bash
-dep ensure -add "go.mongodb.org/mongo-driver/mongo@~1.1.0"
+dep ensure -add "go.mongodb.org/mongo-driver/mongo@~1.1.1"
 ```
 
 -------------------------

version/version.go

@@ -7,4 +7,4 @@
 package version // import "go.mongodb.org/mongo-driver/version"
 
 // Driver is the current version of the driver.
-var Driver = "v1.1.1+prerelease"
+var Driver = "v1.1.1"