0.21.15: Welcome WordPress 5.0 and two new locales
Translations: * For Icelandic translation thanks to Gunnar Geir Johannsson <gunnargj@gmail.com> * For Hebrew translation thanks to Noam Lederman <noaml@noamlederman.co.il> Internals: * Update compatibility testing to make sure latest WP 5.0 is compatible. Nothing changed in functionality. * Avoid circle-ci and move multisite testing to travis.