Rejigged the README file
Refactor of models.py; Moved curl tests into test_api.py

Changed the fields in a service to be Report field instead of
dictionaries to allow validation on their content. Added some more
documentation.
Started to move the curl_* scripts to test_api.py to have their
content in python to start creating a proper integration test
Merge branch 'master' of https://github.com/taarifa/taarifa_backend into map