Fix "overprovision" property name
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Merged. In the future, please make sure to include all of the changes for the PR in either the title or description (i.e. in this case, mention that description spaces were fixed and the CreateOption and Caching definitions were moved to the definition section)
[![Build Status](https://travis-ci.org/AutorestCI/azure-sdk-for-ruby.svg?branch=RestAPI-PR588)](https://travis-ci.org/AutorestCI/azure-sdk-for-ruby) https://github.com/Azure/azure-sdk-for-ruby/pull/488
[![Build Status](https://travis-ci.org/AutorestCI/azure-sdk-for-python.svg?branch=RestAPI-PR588)](https://travis-ci.org/AutorestCI/azure-sdk-for-python) https://github.com/Azure/azure-sdk-for-python/pull/816
[![Build Status](https://travis-ci.org/AutorestCI/azure-sdk-for-node.svg?branch=RestAPI-PR588)](https://travis-ci.org/AutorestCI/azure-sdk-for-node) https://github.com/Azure/azure-sdk-for-node/pull/1923