* Updates to stub generation
* More idiomatic fixes from PHP team
* Moved tests from src/tests -> tests, got rid of extension-only tests
* fixed up test paths, regenerated arginfo
* added credentials API, disabled FFI backend for now
* Added CredentialsTest
* Added support for specifying CMAKE_BUILD_TYPE on the command line
* Added support for AwsCredentials and StaticCredentialsProvider
* Updated to latest aws-crt-ffi, updated EventLoopGroup/options init
* Removed test-ci target, just use test for everything now
* Added event_loop_group API to CRT/stubs
* Removed headers (all generated) from format-check
* Added the ability to force extension vs FFI
* make test will now trigger composer run test/phpunit, and force tests with both FFI and extension
* Updated builder version, removed redundant php7 test run
* Removed type annotations that anger php5, limited backends on php5
* mv src -> ext, lib -> src to be more in line with PHP module expectations
* Fixed dependency for ffi test
* Fixed path in format-check to C source
* CRT will now try the extension first, then FFI