Tag to be used with the master branch of atlas/athena. Update(s) since 2.0.82: - Added Findimportlib_metadata.cmake and FindSQLite3.cmake to AtlasLCG; - Updated flake8 to version 3.8.4; - Updated the CheckerGccPlugins code to take certain function attributes correctly into account; - Added stomp.py as a new external to Externals/PyModules; - Updated the default path that LCG nightlies would be searched under; - Added various updates for ARM 64 build compatibility.