gitignore: ensure utest.cpp not ignored

Couldn't see test/utest.cpp in my Atom IDE. It doesn't show things that
match in the .gitignore file. Update the .gitignore to be specific on
what to ignore with the unit tests.

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: Ifbbabdadad9252ac1596194129a6f76a3d6a36ab
diff --git a/.gitignore b/.gitignore
index 7168564..d32cfcc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,4 +28,5 @@
 stamp-h1
 test-driver
 *.log
-utest*
+utest
+utest.trs