Bump isort from 4.3.4 to 5.5.2#146

dependabot-preview[bot] wants to merge 1 commit intomasterPyconUK/2019.pyconuk.org:masterfrom

dependabot/pip/isort-5.5.2PyconUK/2019.pyconuk.org:dependabot/pip/isort-5.5.2Copy head branch name to clipboard