Propose and implement unit test framework

Enable use of GoogleTest and created a sample unit test case.

Change-Id: Ie370745a32777d4ed81ee24145364029c8e7bf02
Signed-off-by: Matthew Barth <msbarth@us.ibm.com>
diff --git a/sample.h b/sample.h
new file mode 100644
index 0000000..6ff3cf9
--- /dev/null
+++ b/sample.h
@@ -0,0 +1,6 @@
+#ifndef GTEST_SAMPLE
+#define GTEST_SAMPLE
+
+int Factorial(int n);
+
+#endif