Update prometheus and grafana version in requirement.yaml file to be compatible with k8s v1.16
Update prometheus and grafana version in requirement.yaml file to be compatible with k8s v1.16

Signed-off-by: hmkim <4861a1d1bfbc09eb374397b3534884d138968224@popcornsar.com>

codenvy/che,codenvy/che,codenvy/che,codenvy/che