Bump cvxpy from 1.1.5 to 1.1.6 (AtsushiSakai#421)

Bumps [cvxpy](https://github.com/cvxgrp/cvxpy) from 1.1.5 to 1.1.6.
- [Release notes](https://github.com/cvxgrp/cvxpy/releases)
- [Changelog](https://github.com/cvxgrp/cvxpy/blob/master/CHANGELOG.md)
- [Commits](cvxgrp/cvxpy@v1.1.5...v1.1.6)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

requirements.txt

@@ -2,4 +2,4 @@ numpy == 1.19.2
 scipy == 1.5.2
 pandas == 1.1.3
 matplotlib == 3.3.2
-cvxpy == 1.1.5
+cvxpy == 1.1.6