[2/4] mesos git commit: Implemented idempotency for agent resource provider config API calls.

Implemented idempotency for agent resource provider config API calls. `ADD_RESOURCE_PROVIDER_CONFIG`, `UPDATE_RESOURCE_PROVIDER_CONFIG` and `REMOVE_RESOURCE_PROVIDER_CONFIG` now return 200 for identical repetivite calls. Review: https://reviews.apache.org/r/66325 Project:

[2/4] mesos git commit: Implemented idempotency for agent resource provider config API calls.

Implemented idempotency for agent resource provider config API calls. `ADD_RESOURCE_PROVIDER_CONFIG`, `UPDATE_RESOURCE_PROVIDER_CONFIG` and `REMOVE_RESOURCE_PROVIDER_CONFIG` now return 200 for identical repetivite calls. Review: https://reviews.apache.org/r/66325 Project: