Fix 7TV zero-width emotes not working

[tommyxchow]

Fixes #290.

This PR makes it so that we parse the flags field from the 7TV V3 API to check if an emote is zero-width

Previously, the tags field was being parsed to determine if it was zero-width. Turns out, not all zero-width emotes have this set (the tags are probably for something else, like for rendering/filtering on clients).

It doesn't seem to be documented, but based on looking at different emotes in the responses, the flags field appears to be responsible for the zero-width ability. If set to 0 it means a normal emote and 1 means zero-width. This field is now checked to determine if an emote is zero-width.