Add more explicit console logging + minor fixes

* The checks with keywords such as "Should Not Be Empty", "Should
  Be Equal As"... should have a more explicit message on fail, so that
  the console output shows a clearer failing reason.
* Other minor fixes included in the commit are:
	* The Sadis file comparison to None string.
	* The KUBECTL_CONFIG variable not properly set, altough
	  apparently unused.

Change-Id: I9305ba791dd43c9088a7bcbcc9af568ae127f60f
diff --git a/libraries/utils_vgc.robot b/libraries/utils_vgc.robot
index 65e0912..a9f6186 100755
--- a/libraries/utils_vgc.robot
+++ b/libraries/utils_vgc.robot
@@ -40,7 +40,7 @@
 
 Common Test Suite Setup
     [Documentation]    Setup the test suite
-    Set Global Variable    ${KUBECTL_CONFIG}    export KUBECONFIG=%{KUBECONFIG}
+    Set Global Variable    ${KUBECTL_CONFIG}    %{KUBECONFIG}
     Set Global Variable    ${VOLTCTL_CONFIG}    %{VOLTCONFIG}
     ${k8s_node_ip}=    Evaluate    ${nodes}[0].get("ip")
     ${VGC_REST_IP}=    Get Environment Variable    VGC_REST_IP    ${k8s_node_ip}
@@ -78,7 +78,7 @@
     #send sadis file to vgc
     ${sadis_file}=    Get Variable Value    ${sadis.file}
     Log To Console    \nSadis File:${sadis_file}
-    Run Keyword Unless    '${sadis_file}' is '${None}'    Send File To VGC    ${sadis_file}   # apps/
+    Run Keyword Unless    '${sadis_file}' == '${None}'    Send File To VGC    ${sadis_file}   # apps/
     Set Suite Variable    ${num_all_onus}
     Set Suite Variable    ${num_olts}
     Set Suite Variable    ${list_olts}