Fix typo in CLI proxy module

An exception was defined using def instead of class statement, fixing
this.

Also do some formatting adjustments like using single quote for string
in the entire module and some spell fixes.
Merge pull request #1308 from elyezer/cli-proxy

Fix typo in CLI proxy module
Updated docstrings and addressed review comments in pr 1295
updated CV module with factory and with api's(for dependent entities)
Merge pull request #1312 from sghai/comments_1295

Updated docstrings and addressed review comments in pr 1295
Merge pull request #1310 from sghai/cv-module

Updated CV module with factory and with api's(for dependent entities)