Bump github.com/onsi/ginkgo from 1.14.2 to 1.15.2

Bumps [github.com/onsi/ginkgo](https://github.com/onsi/ginkgo) from 1.14.2 to 1.15.2.
- [Release notes](https://github.com/onsi/ginkgo/releases)
- [Changelog](https://github.com/onsi/ginkgo/blob/master/CHANGELOG.md)
- [Commits](onsi/ginkgo@v1.14.2...v1.15.2)

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

go.mod

@@ -6,7 +6,7 @@ require (
 	github.com/Azure/go-autorest/autorest/to v0.4.0
 	github.com/giantswarm/apiextensions v0.4.20
 	github.com/go-logr/logr v0.1.0
-	github.com/onsi/ginkgo v1.14.2
+	github.com/onsi/ginkgo v1.15.2
 	github.com/onsi/gomega v1.10.3
 	github.com/pkg/errors v0.9.1
 	github.com/stretchr/testify v1.6.1