Update version to v1.4.0-beta1

Divjot Arora · Divjot Arora · commit c69a0ab471a1 · 2020-04-10T14:58:27.000-04:00
diff --git a/version/version.go b/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 = "v1.4.0+prerelease"
+var Driver = "v1.4.0-beta1"
