Feature/autogenerate

This pull request add a scripts directory with the generate_sdk_methods.py script and readme included. The script auto generates the SDK methods in the folder canvas_sdk/methods. The auto generated files are also included but should be ignored for the code review. The file to be reviewed is really only the generate_sdk_methods.py. 
I think you should consider using the "with" construct when writing to the file here.  Something like:
with open(...) as f:
    f.write(....)
It guarantees file closure in spite of any exceptions that may occur, and it's recommended in the python docs.