Fix getStickerSet (#836)

Added tests for ServerResponse of getStickerSet.

getStickerSet actually returned a chat object, instead of the intended StickerSet object.

This fixes #836

Prevent redefine constant BASE_PATH

Add defined for not redefine constant BASE_PATH

Improve admin send commands

Fix typo and anchor

Allow running getUpdates without database connection

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