Add missing emoji symbols

Still missing are:
- bowtie
- envelope_with_arrow
- feelsgood
- finnadie
- goberserk
- godmode
- hurtrealbad
- metal
- neckbeard
- octocat
- pencil
- rage1
- rage2
- rage3
- rage4
- shipit
- squirrel
- suspect
- trollface
Merge pull request #5 from jridgewell/emoji_symbols

Add missing emoji symbols