CHANGELOG.md: Add entry for v0.17.0
CHANGELOG.md: Add entry for v0.17.0

brancz/prometheus-operator,coreos/prometheus-operator,gianrubio/prometheus-operator,jescarri/prometheus-operator,gianrubio/prometheus-operator,gianrubio/prometheus-operator,brancz/prometheus-operator,jescarri/prometheus-operator,coreos/prometheus-operator,brancz/prometheus-operator