Description of problem:
Any time when wallaby modify-node is run it prints following error:
fatal:  undefined method `size' for nil:NilClass
Moreover required changes are not performed.

Version-Release number of selected component (if applicable):
wallaby-utils-0.16.3-1

How reproducible:
100%

Steps to Reproduce:
1. run modify-node for some node in store, try to change annotation
# wallaby modify-node node --annotation 'test'
fatal:  undefined method `size' for nil:NilClass

# echo $?
1

# wallaby show-node node
Console Connection Established...
node
  name:  "node"
  provisioned:  true
  last_checkin:  0
  last_updated_version:  1357733570399055
  memberships:  []
  annotation:  ""
  features:  []
  params:  {}

  
Actual results:
The tool prints error

Expected results:
The operation should end successfully without any error

Additional info:
Even without any change it prints error

# wallaby modify-node node
fatal:  undefined method `size' for nil:NilClass