v0.2.0

• added exception handling for link's on_start and on_shutdown
• renamed APSPlanner to ApsPlanner. Old name will be removed in v1.0.0
• added link interval coercion for integers and floats
• renamed Update.index to Update.transfer_number
• renamed Link.name to Link.tags. Old name will be removed in v1.0.0
• added support for Python versions 3.6 to 3.9 and a version support table to the Readme
• renamed catch_exceptions to ignore_exceptions. Old name will be removed in v1.0.0
• added circleci automated branch testing
• added two advanced examples - Twitter Inlet and Elasticsearch Outlet
• in Python 3.8+ replaced asynctest with unittest.mock.AsyncMock
• Autopep'ed the entire Python codebase