Add getter for global Viper
diff --git a/viper.go b/viper.go
index cdf2113..f17790e 100644
--- a/viper.go
+++ b/viper.go
@@ -450,6 +450,11 @@
 	v.typeByDefValue = enable
 }
 
+// GetViper gets the global Viper instance.
+func GetViper() *Viper {
+	return v
+}
+
 // Viper is essentially repository for configurations
 // Get can retrieve any value given the key to use
 // Get has the behavior of returning the value associated with the first