Isitfit

- enh: move tests into `isitfit/tests`
- enh: add dockerfile to test in clean environment
- enh: move DotMan to separate file (out of utils) with functional tests

- feat: check latest version with `outdated` and ask users to upgrade
- feat: use custom domain api.isitfit.io instead of amazonaws endpoint for `isitfit tags suggest --advanced`
- feat: use matomo cloud to collect anonymous usage statistics

- bugfix: pyarrow upgraded to 0.15.0 after report in 6

- enh: replace ValueError with IsitfitError
- feat: `isitfit tags push csv_filename`

- hotfix: still had bug with display df hotfix
- why do I release before testing!?!?

- hotfix: wrong import for `display_df`