Bump lavalink from 3.1.1 to 3.1.2

Bumps [lavalink](https://github.com/Devoxin/Lavalink.py) from 3.1.1 to 3.1.2.
- [Release notes](https://github.com/Devoxin/Lavalink.py/releases)
- [Changelog](https://github.com/Devoxin/Lavalink.py/blob/master/make_release.bat)
- [Commits](https://github.com/Devoxin/Lavalink.py/commits)

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

Author: dependabot-preview[bot]

requirements.txt

@@ -7,7 +7,7 @@ certifi==2019.11.28
 chardet==3.0.4
 discord.py==1.4.1
 idna==2.8
-lavalink==3.1.1
+lavalink==3.1.2
 multidict==4.7.4
 mysql-connector==2.2.9
 python-dotenv==0.10.5