Fix create-ns.sh error (fix #1085)

[seokho-son]

Fix #1085

Test

son@son:~/go/src/github.com/cloud-barista/cb-tumblebug/src/testclient/scripts/2.configureTumblebug$ ./create-ns.sh -x t01-ns-with-x

####################################################################
## 2. Namespace: Create (-x option for NameSpace Name)
####################################################################

{
  "id": "t01-ns-with-x",
  "name": "t01-ns-with-x",
  "description": "NameSpace for General Testing"
}

son@son:~/go/src/github.com/cloud-barista/cb-tumblebug/src/testclient/scripts/2.configureTumblebug$ ./create-ns.sh -f ../testSet.env -x t02-ns-with-f-x

####################################################################
## 2. Namespace: Create (-x option for NameSpace Name)
####################################################################

{
  "id": "t02-ns-with-f-x",
  "name": "t02-ns-with-f-x",
  "description": "NameSpace for General Testing"
}

son@son:~/go/src/github.com/cloud-barista/cb-tumblebug/src/testclient/scripts/2.configureTumblebug$ ./create-ns.sh -f ../testSet.env t03-ns-without-x

####################################################################
## 2. Namespace: Create (-x option for NameSpace Name)
####################################################################

{
  "message": "CreateNs(); The namespace ns01 already exists."
}

son@son:~/go/src/github.com/cloud-barista/cb-tumblebug/src/testclient/scripts/2.configureTumblebug$ ./create-ns.sh t04-ns-no-param

####################################################################
## 2. Namespace: Create (-x option for NameSpace Name)
####################################################################

[Warrning] Invalid option [t04-ns-no-param]

[Usage] ./create-ns.sh -param value -param value
[Example] ./create-ns.sh -n myname01 -f ../testSet.env

 -n [postfix of resources to generate and retrieve] (ex: -n myname01, default: dev01)
 -f [file path to describe a cloud test set] (ex: -f ../testSet01.env, default: ../testSet.env)

 -c [specific cloud type] (ex: -c aws, optional)
 -r [index of a specific zone of the cloud type] (ex: -r 3, optional)

 -x [any value passed to a parameter of the command] (ex: -x vmid01, optional)
 -y [any value passed to a parameter of the command] (ex: -y 3, optional)
 -z [any value passed to a parameter of the command] (ex: -z file, optional)