DISCLAIMER 1: Glvrd API doesn't seem to be suited for non-browser-plugin scenarios, so please do not consider this library acceptable for production usage.
DISCLAIMER 2: Glvrd API may change once in a while; this code is for August-2016-API version.
Many thanks to @SammyVimes for advice in API coverage with Retrofit2 and Telegram Bot API code examples in gopstopbot project.