Add update image tests

*Updated update image module to reflect cloud cafe changes
*Updated modules aesthetic consistency
*Reduced the number of lines in update_image smoke test
*Updated validation in update_image smoke test to allow for full validation
*Removed varaibles for setting true/false

Change-Id: I237b4692f820d0167e3803d916349074fe3a57dd
Add create image and create image negative tests

*Updated create image module to reflect cloud cafe changes
*Updated create image negative module to reflect cloud cafe changes
*Updated modules aesthetic consistency
*Removed happy_path from test name
*Removed create_images and post_images modules as tests are covered elsewhere
*Removed manually parsing of ISO8601 through a random string
*Moved parsing of created_at and updated_at properties to the imade model
*Moved retrivial of created_at_offset and updated_at_offset to images behavior
*Moved validation of core properties to seperate method
*Changed method name for retrieving the creation offset more generic

Change-Id: I2660f99e9e938eacc6091d7f6794b89636babddb
Merge "Add create image and create image negative tests"
Merge "Add update image tests"