docs: fix typo node_js docs (google#117)

This PR corrects a typo in the comment.

node_js.go

@@ -7,6 +7,6 @@
 package uuid
 
 // getHardwareInterface returns nil values for the JS version of the code.
-// This remvoves the "net" dependency, because it is not used in the browser.
+// This removes the "net" dependency, because it is not used in the browser.
 // Using the "net" library inflates the size of the transpiled JS code by 673k bytes.
 func getHardwareInterface(name string) (string, []byte) { return "", nil }