Add MySQL driver to dependencies

Author: djablonski

Gopkg.toml

@@ -2,6 +2,7 @@ required = [
     "github.com/emicklei/go-restful",
     "github.com/onsi/ginkgo", # for test framework
     "github.com/onsi/gomega", # for test matchers
+    "github.com/go-sql-driver/mysql", # for MySQL access
     "k8s.io/client-go/plugin/pkg/client/auth/gcp", # for development against gcp
     "k8s.io/code-generator/cmd/client-gen", # for go generate
     "k8s.io/code-generator/cmd/deepcopy-gen", # for go generate