Bump tabulate from 0.8.3 to 0.8.7

Bumps [tabulate](https://github.com/astanin/python-tabulate) from 0.8.3 to 0.8.7.
- [Release notes](https://github.com/astanin/python-tabulate/releases)
- [Changelog](https://github.com/astanin/python-tabulate/blob/master/CHANGELOG)
- [Commits](https://github.com/astanin/python-tabulate/commits/v0.8.7)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

requirements.txt

@@ -7,7 +7,7 @@ safety==1.8.5
 sklearn==0.0
 ta==0.4.5
 TA-Lib==0.4.17
-tabulate==0.8.3
+tabulate==0.8.7
 tox==3.13.2
 pylint==2.3.1
 pyre-check==0.0.39