Implement a mechanism for preprocessing HTTP requests

[wznira]

[JaewookByun]

Thank you for contributing to this repository with an extension for authentication, logging, and monitoring.
You guys can create 'epcis-extension' directory with a same level of 'epcis-docker' and 'epcis-server'.
The extension should provide all the methods in a standard interface such as
POST /epcis/capture, POST /epcis/events, POST /epcis/query while each method additionally requires
information for authentication, request/response to/from epcis-server, may you can log and monitor during the extension runs.

There will be two options in running oliot epcis in the future.
(1) run epcis-server and epcis-extension and access to epcis-extension to enjoy authentication, logging, monitoring, and core functionality
(2) run epcis-server only for existing users not wanting extensions.

You can pull request with the modification on 'epcis-extension' directory.
Please do not modify the other directory.

Thank you again!

[JaewookByun]

Basic steps for the contribution

1. Fork /JaewookByun/epcis
2. Make changes
3. Pull requests