Bump MaxConcurrentReconciles for ConfigMap controller

Description

Given the ConfigMap controller now watches/reacts to multiple ConfigMap resources, WMCO should be able to concurrently process events.

For example, if WMCO is busy processing the instances ConfigMap, there can be a period of time in which the services ConfigMap could have incorrect contents, which could then be picked up by WICD running on various instances.

Engineering Details

• in configmap_controller builder, add `.WithOptions(controller.Options{MaxConcurrentReconciles: 2})`
• we need to ensure one instance is only being accessed as part of one reconciliation at a point in time, which may require a lock surrounding instance SSH access
• e2e test concurrent processing of events does not break anything (e.g. what happens when WMCO gets events to deconfigure and configure the same instance at the same time?)

Acceptance Criteria

• WMCO is able to concurrently process events on our watched ConfigMaps without any exists functionality breaking
• e2e test validating this