Several emojis show up as black and white variants

The ones I've identified so far is `:sunny:`, `:cloud:` and `:snowflake:`. All 3 needs a unicode variant selector `\U0000FE0F`. I tested 30-ish emojis and haven't found any that fails with the variant selector yet.

Would you accept a PR that adds `\U0000FE0F` to either those specifically or to all emojis? 
