v2.0.13

This bugfix release irons out some wrinkles that have been discovered during usage:

• Fix for handling search responses with missing data stanza but that contain a next token for another page of results. #464
• Stream diagnostics now to go stderr to not interfere with JSON being written to stdout. #456
• twarc can be run from the command line as a module now: e.g. python -m twarc2 search barackobama #455
• twarc2 command help text indicates times are UTC