Sippycup

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- use SIPPYCUP_SCRIPT_NAME_BASE when generating PATH_INFO
- switch to a docker-compose based development environment
- clean up Makefile
- clean up CI config
- implement SAM in demo CloudFormation template for demo app

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- use case insensitive search for Content-Type header in request event
- added a test to ensure POST requests work as expected

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- fix a bug where a TypeError is always raised when no stage variables are
defined

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- fixed a bug where QUERY_STRING was initialized as None instead of an empty
string. This would break things like Flask's request.args.get('something')
if no query params were in the request

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- added support / workaround for setting multiple cookies

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- added support for Python 3.6 (Thanks to PJ Santoro! -
https://github.com/abigperson/)
- use API Gateway's resource path when configuring WSGI environment's
SCRIPT_NAME and PATH_INFO in order to support nested resources
- hide accountId in demo app
- added CloudFormation template to provision AWS resources required for
setting up demo app
- support for specifying SCRIPT_NAME so that redirection and URL generation
work as expected when base path mapping is being used in API Gateway. This
is done by setting a stage variable named SIPPYCUP_SCRIPT_NAME_BASE. See
README for additional details.