Replace resource.txt with resource.robot

Change-Id: I4d2afd35645880e33a31644cd717bbeae55666f0
Signed-off-by: Sandhya Somashekar <sansomas@in.ibm.com>
diff --git a/syslib/utils_os.robot b/syslib/utils_os.robot
index 89a5d5e..9c060df 100755
--- a/syslib/utils_os.robot
+++ b/syslib/utils_os.robot
@@ -8,7 +8,7 @@
 Resource           ../lib/utils.robot
 Resource           ../lib/state_manager.robot
 Resource           ../lib/rest_client.robot
-Resource           resource.txt
+Resource           resource.robot
 Library            OperatingSystem
 Library            DateTime