Add account/update_profile_banner endpoint
Added optional parameter form_field to _pack_image
Accept 200, 201, and 202 as non-error response codes
Added unit test for update_profile_banner
Added example banner image
Make error code check use a range of values in binder.py
Merge branch 'master' into add_update_banner
Merge branch 'master' into add_update_banner
Merge pull request #297 from Aaron1011/add_update_banner

Add account/update_profile_banner endpoint