Improvements to stc command

Add color for interactive sessions if stcColor is not set.
export ONOS_USE_SSH=true for stc tests and then reset it original value

Change-Id: I90d8c95efa91fbdeb97c3f33d601fef4d4bcb0f2
diff --git a/tools/test/bin/stc b/tools/test/bin/stc
index fe8a5af..9f0596a 100755
--- a/tools/test/bin/stc
+++ b/tools/test/bin/stc
@@ -15,9 +15,19 @@
 [ ! -f $scenario ] && scenario=$scenario.xml
 [ ! -f $scenario ] && echo "Scenario $scenario file not found" && exit 1
 
+# Remove the test name from the list of parameters, if one is specified
 [ $# -ge 1 ] && shift
 
-[ -t 1 ] && stcColor=true || unset stcColor
+# If stcColor is not set, we will enable color if this is an interactive session
+[ -t 1 ] && interactive=true || interactive=false
 
+# stc requires that ONOS_USE_SSH=true, but we will store the old value and reset it after
+sshSet=$([ -z ${ONOS_USE_SSH+x} ]) && oldSSH=$ONOS_USE_SSH
+export ONOS_USE_SSH=true
+
+# Run stc
 [ -z "$stcDebug" ] && DEBUG_OPTS=""
-java $DEBUG_OPTS -jar $JAR $scenario "$@"
+stcColor=${stcColor:-$interactive} java $DEBUG_OPTS -jar $JAR $scenario "$@"
+
+# Reset the old value of ONOS_USE_SSH
+[ $sshSet ] && export ONOS_USE_SSH=oldSSH || unset ONOS_USE_SSH