Update README.md (#765)

fix #756

Undoes this pr? #710

Running `go get github.com/go-playground/validator/v10` definitely seems to be the right command. Go getting without the version pulls 9 or just the master. Also importing without the version does not use the current version (v10 at the time of this pr)

Co-authored-by: Dean Karn <Dean.Karn@gmail.com>

README.md

@@ -27,11 +27,11 @@ Installation
 
 Use go get.
 
-	go get github.com/go-playground/validator
+	go get github.com/go-playground/validator/v10
 
 Then import the validator package into your own code.
 
-	import "github.com/go-playground/validator"
+	import "github.com/go-playground/validator/v10"
 
 Error Return Value
 -------