Bump discord-py from 1.3.1 to 1.3.3

Bumps [discord-py](https://github.com/Rapptz/discord.py) from 1.3.1 to 1.3.3.
- [Release notes](https://github.com/Rapptz/discord.py/releases)
- [Commits](https://github.com/Rapptz/discord.py/compare/v1.3.1...v1.3.3)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

requirements.txt

@@ -8,7 +8,7 @@ dblpy==0.3.4
 discord==1.0.1
 git+https://github.com/Rapptz/discord-ext-menus@master
 git+https://github.com/CraftSpider/dpytest@master
-discord.py==1.3.1
+discord.py==1.3.3
 entrypoints==0.3
 flake8==3.7.9
 fonttools==4.5.0