Updated README for Prometheus 2.x (#1134)
Updated README for Prometheus 2.x (#1134)


Aloomaio/alertmanager,Aloomaio/alertmanager,prometheus/alertmanager,tyrken/alertmanager,tyrken/alertmanager,prometheus/alertmanager,tyrken/alertmanager,GoogleCloudPlatform/alertmanager,tyrken/alertmanager,Kellel/alertmanager,Aloomaio/alertmanager,GoogleCloudPlatform/alertmanager,prometheus/alertmanager,Kellel/alertmanager,GoogleCloudPlatform/alertmanager,prometheus/alertmanager,GoogleCloudPlatform/alertmanager,Kellel/alertmanager