create fallback gtest subproject dependency

Allows project to be built and tested locally.

Signed-off-by: Zane Shelley <zshelle@us.ibm.com>
Change-Id: I0965581e5b2bc006a0edfcd05a6fea996f3f6ec2
diff --git a/.gitignore b/.gitignore
index 547b6ed..59f76fd 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 *.sw*
 /build
+/subprojects/googletest