Version 1.2.0

• Merge pull request #60 from nloadholtes/nloadholtes_python3
• Support easy overlay/underlay construction
• Skip test_restore and test_upload_mapping if no api_key/api_secret
• Support upload_mappings api
• Support restore api
• Support 'invalidate' in rename and 'invalidate' and 'context' in explicit
• Support aspect ratio transformation param
• Adding double quotes to prevent python 2.x from printing empty parens
• Adding parens to print for python 3 compatibility
• Merge pull request #59 from nloadholtes/patch-1
• Doc update
• Merge pull request #58 from netman92/patch-1
• Fixed typo in readme.md
• Merge pull request #46 from rtrajano/master
• Merge branch 'ZeroCater-master'
• get_prep_value returns default instead of None
• Added len function to CloudinaryImage
• Add version script