Increase the version.

Author: paulpartington-cti

composer.json

@@ -22,7 +22,7 @@
     "satooshi/php-coveralls": "^1.0",
     "phpunit/phpunit": "4.1.0"
   },
-  "version": "0.15.0-dev",
+  "version": "0.15.1-dev",
   "autoload": {
     "files": [ "registration.php" ],
     "psr-4": {