Add unit test for ReadFileIntoMemory and WriteFileFromMemory

The code is refactored to support mocking the transferDataHost API.
Unit testcases are added for ReadFileIntoMemory and WriteFileFromMemory
responder implementations.

Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>

Change-Id: Iab9966a7aea602cc2abcdf386f077001368e66d9
diff --git a/.gitignore b/.gitignore
index ba334df..c3d3d00 100644
--- a/.gitignore
+++ b/.gitignore
@@ -60,4 +60,6 @@
 /test-suite.log
 /test/*.gcda
 /test/*.gcno
-/test/libpldm_fileio_test
+/test/libpldmoem_fileio_test
+/test/libpldmoemresponder_fileio_test
+