IOS swift push unit tests (5.1)

Closed Quentin Arguillere requested to merge feature/swift_push_tests_5_1 into release/5.1

Add disable_CU_environment flag that can be set in the liblinphone tester. If true, then some asserts won't be launched, allowing the use of LinphoneCoreManager in test outside of the linphone tester environment

Merge request reports