Implement part of BmcEpoch

Add BmcEpoch which inherits EpochBase and will handle times for BMC,
it is partly implemented.

Add unit test cases to test basic functions.

Change-Id: Ia5e4d0f884156d238f3f84df490a2efbce43e89a
Signed-off-by: Lei YU <mine260309@gmail.com>
diff --git a/test/Makefile.am b/test/Makefile.am
index 66e1ae5..26c4c15 100644
--- a/test/Makefile.am
+++ b/test/Makefile.am
@@ -6,7 +6,8 @@
 check_PROGRAMS += test
 
 test_SOURCES = \
-    TestEpochBase.cpp
+    TestEpochBase.cpp \
+    TestBmcEpoch.cpp
 
 test_LDADD = $(top_builddir)/libtimemanager.la