Add simple documentation to readme

Fix method call for sending messages with /sendtochannel command.

Bot API 3.6

Add streamable parameter to InputMediaVideo.

Update scripts lines to work on both Unix and Windows

Use trusty to enable HHVM and add PHP 7.2 to the mix.

 Fix warning when selectTelegramUpdate() returns bool here

Update contact info

Do not process duplicated updates, prevent stopping the script

Update composer dependencies and fix sniffed code.

Fix empty date for User and Chat entities

Allow empty string for `switch_inline_query` parameters

Fix payment related entity relations and types.

Improve changelog to emphasise SQL migration scripts.