Bump pandas from 1.3.0 to 1.3.1

Bumps [pandas](https://github.com/pandas-dev/pandas) from 1.3.0 to 1.3.1.
- [Release notes](https://github.com/pandas-dev/pandas/releases)
- [Changelog](https://github.com/pandas-dev/pandas/blob/master/RELEASE.md)
- [Commits](https://github.com/pandas-dev/pandas/compare/v1.3.0...v1.3.1)

---
updated-dependencies:
- dependency-name: pandas
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements.txt

@@ -1,5 +1,5 @@
 numpy==1.21.1
-pandas==1.3.0
+pandas==1.3.1
 
 ccxt==1.53.25
 # Pin cryptography for now due to rust build errors with piwheels