refactor(injector): rename humanize into stringify

modules/facade/src/lang.dart

@@ -21,7 +21,7 @@ class IMPLEMENTS {
 bool isPresent(obj) => obj != null;
 bool isBlank(obj) => obj == null;
 
-String humanize(obj) => obj.toString();
+String stringify(obj) => obj.toString();
 
 class StringWrapper {
   static String fromCharCode(int code) {

modules/facade/src/lang.es6

@@ -19,7 +19,7 @@ export function isBlank(obj){
   return obj == undefined || obj == null;
 }
 
-export function humanize(token) {
+export function stringify(token) {
   if (typeof token === 'string') {
     return token;
   }