Added unit tests for the face processing code

dlib/test/CMakeLists.txt

@@ -44,6 +44,7 @@ set (tests
    entropy_coder.cpp
    entropy_encoder_model.cpp
    example_args.cpp
+   face.cpp
    fft.cpp
    fhog.cpp
    filtering.cpp

dlib/test/makefile

@@ -59,6 +59,7 @@ SRC += ekm_and_lisf.cpp
 SRC += empirical_kernel_map.cpp
 SRC += entropy_coder.cpp
 SRC += entropy_encoder_model.cpp
+SRC += face.cpp
 SRC += fft.cpp
 SRC += fhog.cpp
 SRC += filtering.cpp