face: Fix segfault caused by Face::unregisterPrefix when registeredPrefixId does not exist

Change-Id: I67e86679fc80506bca439a2a8264c485309f97f3
ci: Embedding CI build and test running script

This commit also unifies build and test scripts for Jenkins and Travis CI

Change-Id: I6ee99c51032769629eb2c62b40608033fa9cac78