fixed code duplication, assertion, exceptions, doctstrings, tests
resolved merge conflict related to locators dict
defined variable locators
Merge pull request #266 from sghai/code-changes

Changes made for arch, OS, media, domain, partition table, subnet and roles modules
Fixed Org locators issue identified in automation job and removed an unused import in test_operatingsys.py
Merge pull request #270 from sthirugn/master

Fixed Org locators issue identified in automation job and removed an unu...