Added test-ffi target, use it in CI (#9)

* Added test-ffi target, use it in CI

* Added clang-format config, fixed RETURN_STRING API mismatch

* Skip installing php and packages on the PHP docker images

* Removed al2 job that was never going to work, and compiler tests

* Fixed basic test for extension loading

* Cleaned up lib structure, fixed tests

* use test-ci target to conditionally test in GitHub

* Use v0.8.1 of builder

Makefile.frag

@@ -50,3 +50,14 @@ $(INSTALL_DIR)/lib/api.h: crt/aws-crt-ffi/src/api.h
 
 # Force the crt object target to depend on the FFI library
 src/crt.lo: $(INSTALL_DIR)/lib/libaws-crt-ffi.so
+
+ifeq ($(TEST_FFI),1)
+test-ci: test-ffi
+else
+test-ci: test
+endif
+
+# Test the FFI interface
+test-ffi: $(INSTALL_DIR)/lib/libaws-crt-ffi.so
+	composer update
+	composer run test