Added link to changelog

Author: ghiscoding

readme.md

@@ -499,4 +499,4 @@ License
 * [1.3.15](https://github.com/ghiscoding/angular-validation/commit/24037e4b2e22658e7e2011c022ba4cca26f391d9) `2015-04-08` Fixed #23 If multiple forms exist in the app the errors in 1 form affect validation in the other
 * [1.3.16](https://github.com/ghiscoding/angular-validation/commit/6c419d45bdb00341416d91199003d827259bd5da) `2015-04-09` Accept Merge #3 Fixed removeFromValidationSummary to also remove from 'local' array
 * [1.3.17](https://github.com/ghiscoding/angular-validation/commit/1283a3a7435c70ec0a355ee273c8479e4b9bdabf) `2015-04-11` Added global `$scope.$validationOptions` [Global Options](#global-options) object, for now only has the `debounce` property that be used by both the Directive and Service.
-* [1.3.18]() `2015-04-19` Fixed issue #20 - Error messages shown on submit are non-understandable, this was fixed using $translate promises instead of $translate.instant(). Fixed a few error display on the validationSummary() and checkFormValidity(). Also merged #27 to add Russian
+* [1.3.18](https://github.com/ghiscoding/angular-validation/commit/d4b55741b9635cd5654f44c58c146f4d86b2e512) `2015-04-19` Fixed issue #20 - Error messages shown on submit are non-understandable, this was fixed using $translate promises instead of $translate.instant(). Fixed a few error display on the validationSummary() and checkFormValidity(). Also merged #27 to add Russian