oneOf fix and api_key override kwarg change (#33)

* resolved oneOf issue and updated api_key override keyword-arg

* version bump

CHANGELOG.md

@@ -7,10 +7,21 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 NOTE: For more granular API-specific changes, please see our [API Changelog](https://developers.klaviyo.com/en/docs/changelog_)
 
+## [5.0.0] - revision 2023-07-15
 
+### Changed
+
+- To override the client-level `api_key` for a specific request, you will now need to use the following new keyword arg: `_request_auth`
+  - previously, this keyword arg was called `api_client`
+
+### Fixed
+
+- Fixed errors that were occurring on requests using oneOf schemas
 
 ## [4.0.0] - revision 2023-07-15
+
 ### Added
+
 - Back-In-stock APIs
   - We have added support for subscribing profiles to back-in-stock notifications, for both email and SMS, using the new [create_back_in_stock_subscription](./README.md#create-back-in-stock-subscription) endpoint.  
 - New functionality to Campaigns API
@@ -20,6 +31,7 @@ NOTE: For more granular API-specific changes, please see our [API Changelog](htt
 
 
 ### Changed
+
 - Relationship Standardization
   - We are making a number of changes across endpoints to standardize how we handle [relationships](https://developers.klaviyo.com/en/docs/relationships_) in our APIs and leverage consistently typed objects across endpoints. For example, you can create a profile in our APIs in the same shape, regardless of whether you’re calling the profiles endpoint or the events endpoint.
   - The changes include:
@@ -34,53 +46,70 @@ NOTE: For more granular API-specific changes, please see our [API Changelog](htt
 
 
 ### Removed
-- We removed the `company_id` from the response for [get_template](./README.md#get-template) and [get_templates](./README.md#get-templates). If you need to obtain the company ID / public API key for an account, please use the [Accounts API](./README.md#accounts).
 
+- We removed the `company_id` from the response for [get_template](./README.md#get-template) and [get_templates](./README.md#get-templates). If you need to obtain the company ID / public API key for an account, please use the [Accounts API](./README.md#accounts).
 
 ## [3.0.0] - revision 2023-06-15
+
 ### Added
+
 - Accounts API is now available, this will allow you to access information about the Klaviyo account associated with your API key.
   - `get_accounts`
   - `get_account`
 
 **Note:** You will need to generate a new API key with either the `Accounts` scope enabled or `Full Access` to use these endpoints.
 
 ### Changed
+
 - The names of positional arguments have changed from `[resource_type]_id` to `id` (i.e. `campaign_id` to `id`) for some relationship endpoints. If keyword arguments were used instead of positional arguments for `[resource_type]_id` you might need to slightly refactor the code.
 
 ### Removed
+
 - All `client` endpoint:
   - `create_client_event`
   - `create_client_profile`
   - `create_client_subscription`
+
 ## [2.0.0] - 2023-04-06
+
 ### Added
+
 - Profiles API now returns predictive analytics when calling `get_profile` and `get_profiles` by passing in `additional_fields_profile = ["predictive_analytics"]`.
 
 ### Changed
+
 - Relationship endpoints that were previously grouped together are now split into related-resource-specific endpoints. This means that all relationship endpoints have new function names. 
 
 ### Migration Guide
+
 - To migrate to this latest version, all calls to relationship endpoints need to be updated, as in the following example:
   - `get_campaign_relationships(campaign_id, "tags")` will become `get_campaign_relationships_tags(campaign_id)`.
 
 ## [1.3.1] - 2023-03-09
+
 ### Added
+
 - Added `page_size` support for paging through endpoints that return profiles.
 
 ## [1.2.1] - 2023-02-23
+
 ### Fixed
 - Fixed a bug that caused paging through events to periodically fail.
 
 ## [1.2.0] - 2023-02-23
+
 ### Added
+
 - Added support for Campaigns (which were previously in our Beta API/SDKs).
 
 ### Changed
+
 - Pagination for Flows changed from page offset to cursor.
 
 ## [1.1.0] - 2023-01-25
+
 ### Added
+
 - Added the following endpoints (which were previously in our Beta API/SDKs):
   - Data Privacy
   - All Tags endpoints, as well as the following related resource-specific endpoints:
@@ -89,10 +118,13 @@ NOTE: For more granular API-specific changes, please see our [API Changelog](htt
     - Get Segment Tags
 
 ## [1.0.0] - 2022-10-19
+
 ### Added
+
 - Initial release
 
 ### Changed
+
 - Namespace changes:
   - Pypi package name: `klaviyo–sdk-beta` → `klaviyo-api`
   - Module name: `klaviyo_sdk_beta` → `klaviyo_api`