Pacifica-cartd

Added
- Fix 99 Only Fix Error Files by [dmlb2000](https://github.com/dmlb2000)
- Fix 100 Fix ReadTheDocs Build by [dmlb2000](https://github.com/dmlb2000)
- Pull 104 Remove Requirements Files by [dmlb2000](https://github.com/dmlb2000)
- Pull 98 Namespace and Setup Fixes by [dmlb2000](https://github.com/dmlb2000)

Added
- Pull 92 Update to Pylint 2.0+ by [dmlb2000](https://github.com/dmlb2000)
- Pull 93 Include testing Python 3.7 and 3.8 by [dmlb2000](https://github.com/dmlb2000)

Changed
- Fix 85 Add option to disable cart purge by [dmlb2000](https://github.com/dmlb2000)
- Fix 88 Remove traceback from 404 carts by [dmlb2000](https://github.com/dmlb2000)

Added
- Pull 90 add cart purge subcommand by [karcaw](https://github.com/karcaw)
- Pull 83 Add cart dump command by [karcaw](https://github.com/karcaw)

Changed
- Fix 81 add help for no subcommand by [dmlb2000](https://github.com/dmlb2000)
- Fix 86 drop support for Python 2.7 by [dmlb2000](https://github.com/dmlb2000)
- Fix 84 fix Travis CI by [dmlb2000](https://github.com/dmlb2000)
- Fix 82 update Development Docs by [karcaw](https://github.com/karcaw)

Changed
- Fix 76 Updated testing framework by [dmlb2000](https://github.com/dmlb2000)
- Fix 75 Add cart rebuild command by [dmlb2000](https://github.com/dmlb2000)
- Fix 74 File download retry loop by [dmlb2000](https://github.com/dmlb2000)

Added
- Download of data in the archiveinterface
- Building structure locally to serve the data
- ReadtheDocs supported Sphinx docs
- Backend file structure as directory or single tarfile
- Data checksum validation
- REST API for sending and recieving data
- POST - Create a cart
- GET - Get data in the cart
- HEAD - Get cart status
- DELETE - Delete the cart

Changed