Pylint warning and error fix in GUI file

Changes:
    - Missing class docstring fixed

Tested:
    - python3 -m pylint gui/data/resource_variables.py

Change-Id: If55fc2ccf0f4bc9e278fac1dda3163337d5d5725
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/gui/data/resource_variables.py b/gui/data/resource_variables.py
index e70a324..9f6cf38 100644
--- a/gui/data/resource_variables.py
+++ b/gui/data/resource_variables.py
@@ -7,6 +7,9 @@
 
 
 class resource_variables:
+    r"""
+    Base class for GUI resource related XPATH variables.
+    """
     xpath_textbox_hostname = "//input[@id='host']"
     xpath_textbox_username = "//input[@id='username']"
     xpath_textbox_password = "//input[@id='password']"