- update changelog and composer.lock

[South] Bug fixes

- update version with git grep --name-only '0.74.0-beta5' | grep -v 'CHANGELOG.md' | xargs -i@ sed -i 's/0.74.0-beta5/0.74.0-beta6/g' @

[API] Sprint 47 – Sales & Checkout APIs

 - Clean up unused variable for \Magento\Quote\Api\CartManagementTest::testPlaceOrderForMyCart

 - Fix \Magento\Quote\Api\CartManagementTest by adding rollback to delete created orders
 - Move logic for deleting create quotes to the rollback fixture

[Extensibility] Sprint Bug Fixes

 - merged branches MAGETWO-35023-Code-Coverage-Guest-Sales-And-Checkout-APIs and MAGETWO-36189-SalesCheckoutAPIs-Mine-ParamOverrider for new PR

 - removed delete methods from non-guest versions CartItemRepositoryInterface and Repository

Merge remote-tracking branches 'remotes/origin/MAGETWO-35603-Test-Failures-When-DB-In-Different-Timezone' and 'remotes/origin/MAGETWO-36450-Phrase-Omits-Placeholder-Values' into MAGETWO-22669-Change-Table-Type-To-InnoDB

 - removed delete methods from interface and implementation

[API] MAGETWO-35879: Changed to use LocalizedException in Currency Symbol FetchRates

MAGETWO-36450: Set placeholder as default render for \Magento\Framework\Phrase if no renderer is set.

 - fixed namespace error
 - fixed code formatting issues

 - fix misspellings of overridden in tests to prevent static test failures

Merge branch 'develop' of github.scm.corp.ebay.com:magento2/magento2ce into MAGETWO-35023-Code-Coverage-Guest-Sales-And-Checkout-APIs

Merge branch 'MAGETWO-35023-Code-Coverage-Guest-Sales-And-Checkout-APIs' of github.scm.corp.ebay.com:magento-api/magento2ce into MAGETWO-35023-Code-Coverage-Guest-Sales-And-Checkout-APIs

MAGETWO-36224: Success message is absent while adding product with options from wishlist to shopping cart

- minor changes. removed excessive code

- fixed a typo in a method name

[FearlessKiwis] Added Bundle Product to Catalog Product Data Object

- Fix unit tests to use GuestCartTestHelper

- Fix misspelling of overriden to overridden

Merge branch 'MAGETWO-35023-Code-Coverage-Guest-Sales-And-Checkout-APIs' of github.scm.corp.ebay.com:magento-api/magento2ce into MAGETWO-35023-Code-Coverage-Guest-Sales-And-Checkout-APIs

 - Remove \Magento\Quote\Model\GuestCart\GuestCartManagement::getCartForCustomer
 - Remove $quoteRepository from the parameters of GuestCartManagement::__construct
 - Update unit test accordingly

 - Remove $quoteRepository from the parameters of GuestCartManagement::__construct
 - Update unit test accordingly