feat(isLocale): validate isLocale

- it validates different languages for different geographical location
- Closes validatorjs#954

README.md

@@ -117,6 +117,7 @@ Validator                               | Description
 **isJWT(str)**                         | check if the string is valid JWT token.
 **isLatLong(str)**                      | check if the string is a valid latitude-longitude coordinate in the format `lat,long` or `lat, long`.
 **isLength(str [, options])**              | check if the string's length falls in a range.<br/><br/>`options` is an object which defaults to `{min:0, max: undefined}`. Note: this function takes into account surrogate pairs.
+**isLocale(str)**                       | check if the string is a locale
 **isLowercase(str)**                    | check if the string is lowercase.
 **isMACAddress(str)**                   | check if the string is a MAC address.<br/><br/>`options` is an object which defaults to `{no_colons: false}`. If `no_colons` is true, the validator will allow MAC addresses without the colons. Also, it allows the use of hyphens or spaces e.g  '01 02 03 04 05 ab' or '01-02-03-04-05-ab'. 
 **isMD5(str)**                          | check if the string is a MD5 hash.

index.js

@@ -33,6 +33,8 @@ var _isFQDN = _interopRequireDefault(require("./lib/isFQDN"));
 
 var _isBoolean = _interopRequireDefault(require("./lib/isBoolean"));
 
+var _isLocale = _interopRequireDefault(require("./lib/isLocale"));
+
 var _isAlpha = _interopRequireWildcard(require("./lib/isAlpha"));
 
 var _isAlphanumeric = _interopRequireWildcard(require("./lib/isAlphanumeric"));
@@ -200,6 +202,7 @@ var validator = {
   isJSON: _isJSON.default,
   isEmpty: _isEmpty.default,
   isLength: _isLength.default,
+  isLocale: _isLocale.default,
   isByteLength: _isByteLength.default,
   isUUID: _isUUID.default,
   isMongoId: _isMongoId.default,