Update version information

README.md

@@ -256,7 +256,7 @@ The following table compares __php-iban__ to other PHP projects offering IBAN-re
 
 | Project                                                    | Lic. | Proc | OO  | Began  | Latest | Star | Watch | Fork | Installs | Home culture | Deps    |
 | ---------------------------------------------------------- | ---- | ---- | --- | ------ | ------ | ---- | ----- | ---- | -------- | ------------ | ------- |
-| __php-iban__                                               | LGPL | ✔    | ✔   | 2009   | 2.6.6  | 222  | 24    | 42   | 350k+*   | Global*      | *none*  |
+| __php-iban__                                               | LGPL | ✔    | ✔   | 2009   | 2.6.7  | 222  | 24    | 42   | 350k+*   | Global*      | *none*  |
 | [Iban](https://github.com/jschaedl/Iban)                   | MIT  | ✘    | ✔   | 2013   | 1.3.0  | 50   | 9     | 19   | 178.39k  | German       | lots    |
 | [IsoCodes](https://github.com/ronanguilloux/IsoCodes)      | GPL3 | ✘    | ✔   | 2012   | 2.1.1  | 466  | 22    | 54   | 145k     | French       | lots    |
 | [SepaUtil's](https://github.com/AbcAeffchen/SepaUtilities) | GPL3 | ✘    | ✔   | 2014   | 1.2.3  | 8    | 4     | 3    | 25k      | German       | phpunit |
@@ -330,6 +330,13 @@ Your Help Wanted
 News: June 2018
 ---------------
 
+__[Version 2.6.7](https://github.com/globalcitizen/php-iban/releases/tag/v2.6.7)__ has been released.
+ * Added national checksum implementation for Slovakia (`SK`)
+ * Thanks to @ostrolucky
+
+News: June 2018
+---------------
+
 __[Version 2.6.6](https://github.com/globalcitizen/php-iban/releases/tag/v2.6.6)__ has been released.
  * Fixed generation of voluminous errors in environments without `ini_set` enabled
  * Thanks to @agil-NUBBA